Len has held off on signing any potential offer sheets and is in line to sign Phoenix's proposal at some point before Tuesday "barring an unforeseen change of events," per Wojnarowski.
By signing the offer sheet, Len can become an unrestricted free agent next offseason and would be free to sign with any team.
Phoenix selected Len with the No. 5 overall pick in the first round of the 2013 NBA draft out of Maryland, and he has slowly developed into a serviceable big.
We Owe the Indiana Pacers an Apology
B/R Looks Back on Tracy McGrady Scoring 13 Points in 35 Seconds in 2004
Tracy McGrady Scored the Most Impressive 13 Points of His Career in 35 Seconds
Butler Is the NBA's Biggest Country Music Fan
On This Day in 2012, Kobe Joined Elite NBA Club
NBA Handshake Fails
Is It Officially Panic Time in OKC?
Simmons Finally Faces 'Big Brother' LeBron
Leave Lonzo Alone, He's Only 20
The Boston Celtics Are on Top of the NBA
Gregg Popovich Has the San Antonio Spurs Rolling at Home
It's Early, but Stevens Is the Coach of the Year
Shaq and Chuck Used to Get into It on the Court
LeBron Isn't Worried, but Maybe He Should Be
NBA Superstars Are Cruising by Scoring Milestones
This Lakers Rookie Is Ready to Take Over the NBA
LeBron James Jr. Is More Than Just His Famous Name
Growing Up: Damian Lillard Tells Us How He Improved His Jump Shot as a Kid
Growing Up: the Game That Showed Isaiah Thomas He Could Be an NBA Star
Growing Up: How Kyrie Irving Became One of the League’s Most Lethal Scorers
The 24-year-old native of Ukraine is coming off a 2016-17 season that saw him average 8.0 points, 6.6 rebounds and 1.3 blocks per game, while shooting 49.7 percent from the field.
Although he was more efficient last season, his best statistical campaign came in 2015-16 when he set career highs with 9.0 points and 7.6 rebounds per contest.
Len has shuttled between starting and coming off the bench, and he is likely to primarily be a bench player in 2017-18 with veteran Tyson Chandler serving in a starting role.
While Len will provide needed depth during the upcoming season, he may not have a long-term future in Phoenix due to the other young talent it has in the frontcourt, including Marquese Chriss, Dragan Bender and Josh Jackson.