Mayo can begin negotiating with teams and declare his intent to sign, but nothing official will happen until July 10 when the free agency moratorium ends and the league nails down the salary cap and luxury tax levels.
However, one thing that we can tell for sure is that the shooting guard market is bare, and it looks to be that way for years into the future.
The league is short of solid shooting guards, and with the top-tier guards like James Harden, Kobe Bryant, and Dwyane Wade locked in for the time being, the second-level guys who are free to roam from here to there every few seasons can end up getting big bucks.
Andre Iguodola is at the top of this year's crop, but Mayo has quickly risen to the slot right behind him and possibly even above him in some cases.
He's not as inconsistent as J.R. Smith, he shouldn't demand big money for inefficiency like Monta Ellis and he's nowhere near as enigmatic as Tyreke Evans.
Mayo is a much better shooter than Iggy, and his defensive shortcoming no longer seem to be as evident as he's turned into a more mature player.
Dallas' former shooting guard made 47 percent of his two-point shots last season and put together his best three-point shooting season, cracking the 40 percent mark and officially becoming a good shooter in the eyes of many around the league.
So which team is in need of a scorer from that 2-spot, and of those which make the most sense to land Mayo?
As usual, these looks are meant to be realistic, so most teams who would be good fits for Mayo also must have at least some salary-cap flexibility. My sincerest apologies to the New York Knicks and Los Angeles Lakers.
Charlotte is a barren wasteland of talent—well, at least as far as visible NBA-level talent is concerned at this point—and desperately need a player who can score with some level of efficiency.
As Gerald Henderson becomes a restricted free agent and Ben Gordon's contract finally becomes tradeable in his final season, Mayo could step in and become a consistent scoring option while Michael Kidd-Gilchrist and Kemba Walker continue to grow.
Would it be the perfect place for him to develop as a player? Absolutely not.
Mayo would be in a position where he would be the team's leading scorer in all likelihood, and he would be pressured to shoot a few too many times per game.
However, he would help the Bobcats' scoring average, which came in at a raucous 26th league-wide last season.
They are one of the teams reportedly interested in Mayo, according to a tweet by USA Today's Sam Amick, so there's a distinct possibility here.
Cleveland had a bit of interest in O.J. Mayo back in mid-May, but nothing coming out of their front office with regards to free agency has developed as of yet.
However, he would fill an interesting role for the Cavaliers, who are looking to make the move from lottery-dwellers to playoff contenders this season.
The frontcourt is all but locked up for Cleveland, who just drafted Anthony Bennett and Sergey Karasev to fill in at the power-forward and small-forward roles, but they've still just got two reliable guards.
Mayo could come in and likely snake the starting spot away from Dion Waiters, giving Cleveland a three-man rotation of guys who are all worthy ball-handlers and shooters.
The only problem is that the report about Cleveland's interest in Mayo also states that Cleveland isn't looking to commit long-term money to many players.
Cleveland's summer of interest comes a year from now when they'll have cap space preserved and, they hope, a team that could be transformed into a contender with the addition of a maximum-salary player.
If Mayo wants to grab a one-year deal (which isn't likely) or a longer deal for less money (ditto), Cleveland would be an interesting spot.
Kyle Singler played 25 percent of Detroit's minutes at the shooting-guard spot in 2013. Beyond that, Brandon Knight picked up 17 percent and Kim English played the 2-guard spot eight percent of the time.
Their only true shooting guard, Rodney Stuckey, played 42 percent of the shooting-guard minutes, despite shooting just 40 percent on the season.
Basically, it was a complete train wreck.
Kentavious Caldwell-Pope looks to be coming in to wrestle a few minutes away from Stuckey, but here the Pistons sit without a guard who can both shoot well over 40 percent and play more than 20 minutes a game.
O.J. Mayo can do both. Plus, he can handle the ball a bit and do a bit of picking-and-rolling with Greg Monroe.
Much of New Orleans' summer is dependent on what they're planning with Eric Gordon. He's "very available," according to a source that spoke with Real GM, but no deals have grown legs yet.
While it looks as if New Orleans will try to move him, for what remains to be seen.
Either way, after trading for Jrue Holiday, it's obvious that the two positions to address in question will be the shooting-guard and small-forward spot.
Mayo could slide in nicely to become both an off-ball guard alongside Holiday and a primary ball-handler in his wake.
He's capable of running the pick-and-roll, which Anthony Davis is becoming incredibly adept at running as well, and his shooting would give them a player to throw in the corner and spot up from time to time.
New Orleans' offense could easily go from 25th in the league in 2013 to one of the most fast-paced and unpredictable in 2014.
This one's pretty simple to figure out: Atlanta has about a billion dollars in cap space, Dwight Howard likely isn't coming to town and they've got to spend it somewhere in order to truly reload, rather than rebuild.
While they'll have Lou Williams and likely Jeff Teague under contract next season along with Al Horford (everybody else is up in the air), they need some reliable backcourt shooting to help them adjust to life after Josh Smith (presumably).
Mayo's ability to shoot makes him a solid pairing with Horford to pick-and-roll, pick-and-pop or pick-and-whatever throughout the season.
Plus, with Williams coming off ACL surgery, they would be adding an incredibly durable player, as Mayo has played in every game for four of his first five years in the league.
Best of all, it gives them a third guard to space 32 minutes out to and get solid production from either side of the floor in return.
Monta Ellis' desire to leave the Milwaukee Bucks is not necessarily a bad thing. In fact it could end up being a positive in the long run.
Ellis would have been worth at least $12 million per year against their salary cap, and he would have continued to chuck up shots that he doesn't routinely make with Milwaukee needing backcourt scoring coming from somewhere.
If we learned anything from Mayo in the past season, it's that he's matured much quicker than we would have assumed after his days in Memphis. Sure, he still has his lapses, but he takes wiser shots and doesn't constantly need the ball in his hands to thrive.
A bit of that mentality, along with Mayo's continued belief that he is one of the best shooting guards in the league could go a long way.
Plus, it would be nice to have a shooting guard on the team who can actually shoot from some kind of range.
According to USA Today's Sam Amick, Milwaukee is one of the teams targeting Mayo.
Thanks to a few solid three-point shooting nights near the end of the season, the Minnesota Timberwolves were able to bring their overall three-point percentage over 30 percent for the season.
In other words, they were able to bring it up from historically atrocious, to just a regular level of terrible.
Seven of their players attempted at least 92 three-pointers throughout the season. Kevin Love scraped the bottom of that barrel at 21 percent, and three others clocked in at 29 percent while their three best shooters came in somewhere between 31 and 34 percent from beyond the arc.
While they're bringing in a decent three-point shooter in Shabazz Muhammad, he's hardly enough to turn them around.
Mayo would give the Timberwolves a wing who can shoot and handle his own with the ball on offense and isn't completely incompetent on defense.
As it seems, Minnesota is a bit log-jammed in the backcourt, but bringing in somebody like Mayo would be a huge improvement over J.J. Barea or Luke Ridnour.
Minnesota is one of the teams courting Mayo, according to USA Today's Sam Amick.
Randy Foye started 72 games at the shooting-guard spot for the Utah Jazz in 2013. Anytime a team uses somebody like Foye as more than a spot-up shooter off the bench, a change has to be made.
Lucky for Utah, they're going into an offseason where change isn't only inevitable, but also preferred.
They had a nice squad last season, but running the offense through the frontcourt just didn't work out.
If both Al Jefferson and Paul Millsap end up leaving, suddenly Derrick Favors and Enes Kanter become the focus down low, and an offensive power vacuum develops.
Gordon Hayward can likely pick up a bit of slack, while Favors and Kanter can pick up a bit of slack, but it's going to have to be backcourt improvements to help Utah turn the corner.
Trey Burke looks to be their new point guard (unless they stick to Mo Williams), but a shooting guard who can help handle the ball a bit alongside the rookie out of Michigan while also helping to space the floor would be ideal.
Mayo fits that role to a tee.
Utah has interest in Mayo, according to a report from USA Today's Sam Amick.