The Cardinals will assume the two-year, $21 million option on starting pitcher Adam Wainwright, barring an unforeseen complication in his return from ligament replacement surgery in February, general manager John Mozeliak confirmed Thursday night.

"There is no reason for us not to assume it," Mozeliak said.

Mozeliak described the stance as "unofficial" because the club option doesn't need to be exercised until shortly after the season. Wainwright on Thursday described his rehab as accelerating on a positive slope that will allow him to return to the mound before mid-September. Wainwright recently received clearance to throw from 120 feet on flat ground and is able to one-hand 60-pound weights.

"To date he has had a very, very good rehab. I'm knocking on wood as we speak," Mozeliak said.

The 2010 runner-up for the NL Cy Young Award spoke confidently Thursday of his ability to fully participate in spring training less than a year after requiring Tommy John surgery. Wainwright reiterated a belief that he might be a factor in October should the Cardinals reach postseason play. However, the team's 10-game deficit with 29 games left on the schedule would appear to make the possibility moot.

Wainwright, who turns 30 next Tuesday, agreed to the two-year club option as part of an extension signed prior to the 2008 season. He led the National League with 19 wins in 2009 and won 20 games in 2010. Wainwright finished third in 2009 Cy Young balloting to Tim Lincecum and teammate Chris Carpenter before placing second behind unanimous winner Roy Halladay last November.

The finishes caused the option to automatically vest, according to the contract's terms, but the Cardinals could have exercised an out due to Wainwright ending this season on the disabled list with an arm-related injury.

Mozeliak allowed that Wainwright's ligament replacement complicates rolling the option into a longer extension. "I just don't think the timing of something like that would make sense," Mozeliak said.

The option provides Wainwright $9 million next season and $12 million in 2013, a relative bargain for a pitcher who led the league in wins in 2009 and 2010, won a Gold Glove in 2010 and pitched more than 230 innings each of the past two years. Wainwright posted a 2.63 ERA in 2009 and a 2.42 ERA last season.