While Tommy John surgery has a shorter recovery period for position players than it does for pitchers, who obviously throw more, a lost season and a possible position change could change the fortune of the player ranked No. 6 in the game by Baseball America.
An MRI and exam confirmed that Sano has torn his UCL (ulnar collateral ligament of the elbow). Sources tell me that there is still some worry that there is more extensive damage inside the elbow and that the surgeon, when chosen, will need to check it thoroughly when he goes in.
One source told me that the biggest fear is damage to the articular cartilage of the elbow, which could affect his long-term ability to throw with power. This could necessitate a position change.
The elbow was checked immediately after Sano injured his elbow in an intrasquad game on a simple throw. The doctors were concerned that the UCL had been compromised. Sano had previously hurt his elbow during winter ball, but he had cleared his physical coming into camp.
Since the team knew about the winter injury and monitored it, it is hard to believe that it would not have checked this in addition to the normal pre-camp physical. These physicals are often superficial, but known problem areas are usually checked thoroughly in order to maintain a paper trail for possible insurance and worker's compensation issues down the line.
The normal recovery time for a pitcher having Tommy John surgery is between 10 and 12 months. For a position player, it can be less, as little as six months but normally closer to eight or nine. For more information on the surgery itself and its background, please read this award-winning series of articles.
The Twins' Rob Antony, the assistant general manager who is running the club while Terry Ryan is recovering from cancer surgery, told the media that the team believes Sano will be back to hitting in four months.
Here is Sano himself discussing the upcoming surgery, courtesy of Mike Berardino of the St. Paul Pioneer Press:
But they do not expect Sano to play this season. He may need winter ball again next season, though teams are often reluctant to let rehabbing players play outside close supervision of their own medical staff.
The list of position players who have had Tommy John surgery isn't as extensive as it is for pitchers—but it's not short either. Players like Jose Canseco, Luis Gonzalez, Tony Womack, Shin-Soo Choo and Kyle Blanks have had the procedure. All returned normally and without significant change to their game. However, there's not many in the way of plus-throwers in there.
While Albert Pujols did not have Tommy John surgery, he did damage his ulnar collateral ligament. It forced his move from third base, initially moving him to left field. He was limited in throwing so much that Tony La Russa devised a new relay system, sending shortstop Edgar Renteria deep into the outfield to shorten any throw.
Pujols quickly moved to first base after the throwing because of untenability. He later had nerve transposition surgery on the elbow, but refused to have Tommy John surgery.
The downside for Sano is that he no longer has as many options as Pujols did. Joe Mauer's shift to first base from his previous catcher slot makes it nearly impossible to move Sano there. In fact, Mauer's position was switched in part because Sano was expected to play third. Mauer is athletic enough to hold the position, so those plans may have to shift somewhat if Sano shows any throwing deficits.
The rehab process is very similar for position players as it is for pitchers. Sano should be able to recover, but for a player who has already overcome so much to be in this position, he can't make up the time lost. Along with Byron Buxton, Sano is the vanguard of Terry Ryan's team remake; losing a year won't help, while positional issues may alter the plan altogether.
While Sano should return, there are more questions than answers at this stage.