The Mets are expected to exercise the $5.5 million buyout for Santana for 2014, making the talented left-hander a free agent. If the Mets elect not to buy out Santana, he will be owed $25 million next season.
Alderson said on WFAN radio on Monday that it's a "possibility" the Mets could bring back Santana in 2014. Agent Chris Leible said the sides haven't talked about 2014 yet but that he could see Santana back in Flushing.
"Yeah. Of course," Leible told ESPNNewYork.com.
He added: "We'd be open to speaking, of course, at any time."
Santana, 34, missed this past season after he underwent surgery April 2 to repair a torn anterior capsule in his left shoulder for the second time. He previously had the same surgery on Sept. 14, 2010, and did not return to the majors until April 5, 2012. He last pitched Aug. 17, 2012, against Atlanta.
Leible said Santana is improving and is on schedule but that he did not believe Santana has started throwing yet. He described Santana's rehab as a slow one but said the veteran worked hard over the summer. Leible said the hope is for Santana to be ready for spring training, but they're not committing to a date.
Santana faces a challenge to return to the majors, as few players have undergone that surgery and their careers were never the same afterward. It took Santana 19 months to return from the first surgery, and he's trying to be the first to return from undergoing that surgery twice.
"Johan basically told me he's not going to go out like that. He's going to do everything he can to try and get back and hopeful that he will be able to," Leible said. "He feels good at this point. Until he really starts throwing the ball and pitching off a mound, we're not going to know that. So we'll see. But all signs so far are good, but it's a step-by-step process."
Alderson reiterated Monday that the Mets currently view only three pitchers as locks for their rotation in 2014: Zack Wheeler, Jon Niese and Dillon Gee. While ace Matt Harvey wants to rehab the partial tear to his ulnar collateral ligament and avoid surgery, the team is being cautious in case he needs to undergo Tommy John surgery.
The GM said he would be uncomfortable with relying on a player coming off injury or one of the team's young prospects to fill the final two spots in the rotation, provided Harvey doesn't take one. He said he would be surprised if the Mets chased one of the top pitchers in the free-agent market.
"I don't really know what Johan's thinking. We'll talk to him, I'm sure, over the next couple of weeks, but I think he wants to pitch," Alderson said on WFAN on Monday. "We'll just have to see what the market is for these guys and how much of our resources we want to allocate to somebody coming off injury or somebody you hope was able to pitch for you at a higher level."
Santana signed a six-year, $137.5 million deal with the Mets prior to the 2008 season, but injuries have forced him to miss two full seasons with the organization. He is 46-34 with a 3.18 ERA with the Mets but has made only 109 starts. He threw the franchise's only no-hitter on June 1, 2012, against St. Louis.
Santana went 6-9 for the Mets in 2012, but he struggled as the season progressed, going 0-5 with a 15.63 ERA in his final five starts before landing on the disabled list for the remainder of the year with lower-back inflammation. It marked the first time he finished with a losing record as a starter.
Leible said Santana and the Mets have had a fine working relationship.
"He's unfortunately had some injuries, but when he played, he pitched very well and helped the organization out," Leible said. "There's no problems or anything like that."
Matt Ehalt is a contributor to ESPNNewYork.com.