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LOS ANGELES — John Lackey did not fight it one bit.

His medicals dictated negotiations go down that way. He understood. And for the money he was being assured, it was not much of a sticking point.

Over the course of Lackey's five-year, $82.5 million contract signed with the Boston Red Sox before the 2010 season, he missed an entire season. It was 2012, and a right elbow ligament was the culprit, causing Tommy John surgery and likely Lackey's 6.41 ERA in 2011.

Due to that "significant time" missed, the 13-year veteran is now pitching for the St. Louis Cardinals because an injury clause kicked in at the end of that contract. Only now he is doing it for the league minimum of $507,500 rather than the original $16.5 million average annual value of the deal.

Lackey also happens to be 11 starts into what could be the best season of his career, and the Cardinals are reaping the benefits thanks to a heady contract clause added by the Red Sox after they discovered the right-hander's elbow damage before completing the agreement.

"They found something in my physical, that my elbow had some damage in it for sure, so they wanted to put that [clause] in," Lackey said Thursday at Dodger Stadium, a day after he pitched seven innings and allowed three runs to the Milwaukee Brewers to up his ERA to 2.93 and his FIP to 3.23. "It wasn't a huge deal for me."

It has become a huge deal for the Cardinals, who dealt for Lackey at last season's trade deadline, giving up Allen Craig and Joe Kelly in the process. Rotation depth could have become an issue after St. Louis traded Kelly and Shelby Miller while losing Adam Wainwright for the season to an Achilles injury in April, but Lackey's unexpected performance has allowed the Cardinals to absorb the depletion. It has also helped them hold the majors' lowest rotation ERA (2.91).

"Lackey is a big piece, we knew that going in whether Waino was here or not," manager Mike Matheny said. "We knew we needed another veteran presence in our staff, a guy who can go out there and be a stopper and rack up big innings.

"He's been a very pleasant surprise, too. His stuff is even better than what we saw last year. He's been a guy we're leaning pretty heavy on right now."

What the Cardinals saw last year was not impressive. Lackey, who's won World Series with the Los Angeles Angels and Red Sox, made a decent 21 starts for the Red Sox, putting up a 3.60 ERA and 107 ERA+ before the trade to St. Louis.

Once he got to the seemingly more pitcher-friendly National League, Lackey's ERA pumped up to 4.30, and his ERA+ dripped to 86 in 10 starts. He made two postseason starts, one of them stellar against the Los Angeles Dodgers in the NL Division Series—seven innings, one run, eight strikeouts.

Not much has changed for Lackey this season in terms of how he's gotten to his sub-3.00 ERA. His .283 BABIP is not far off from his previous two seasons of .281 in 2013 and .305 last year, and his line-drive, ground-ball and fly-ball rates are all basically the same as they were a season ago, according to FanGraphs. And while he is inducing a little more soft contact, his hard-hit percentage is again about the same as it was in 2014.

His 78.4 percent strand rate is better than league average (72.5), but not drastically higher than his marks last season (72.6) or in 2013 (76.9).

Matheny could not pinpoint a definitive reason for Lackey's success over the first two months of this season, but he said his command and stuff are better than what he showed in his brief time with the Cardinals last year.

"The ball is jumping out of his hands, and that's really the difference more than anything else, just his ability to be able to hit spots and the kind of stuff he has," Matheny said. "I don't know what was going on last year. He was still good, but it's a different level he's been throwing out there right now."

Lackey himself has not noticed a big difference in his stuff or approach to hitters, although he also thought he was "fine" last season, even with the Cardinals when he had a 4.27 FIP and 1.385 WHIP.

There has been no extra motivation for Lackey, nor is he pitching with any kind of chip because he is a veteran now earning the minimum after accruing more than $108 million over his career.

"Nothing like that," Lackey said. "It was part of my deal. I knew it was coming."

Billy Hurst/Associated Press

The clause, which came as no surprise since it kicked in immediately after the 2012 season, was a big reason the Cardinals went after Lackey. General manager John Mozeliak saw it as more of a reason to acquire him, knowing he'd have him on the cheap for 2015.

There was talk around the MLB Winter Meetings about the Cardinals and Lackey reworking his contract for this season, probably increasing this season's salary and possibly extending the contract, but that never became a reality.

Mozeliak told Rick Hummel of the St. Louis Post-Dispatch in February:

Obviously, the compensation for 2015 was attractive to us. In terms of trying to change that structure, I don't know if both parties are going to find there's a very desirable reason to do that, considering the opportunities that might exist for him entering his free-agent year. I'm not closing the door on anything but I'm not pursuing anything either at this point. I don't feel that either party is pushing, for that matter.

And wisely so for Lackey's side. Whatever is to credit for his effectiveness this season, Lackey has helped St. Louis to the best record in baseball and is helping himself to another free-agent contract that certainly will be worth significantly more than league minimum as long as he continues this trend.

"He's representing himself in a way that's going to earn plenty of reward at the end of it," Matheny said.

All quotes, unless otherwise specified, have been acquired firsthand by Anthony Witrado. Follow Anthony on Twitter @awitrado and talk baseball here.