On his first day in the St. Louis clubhouse, Aardsma made it a point to speak with the Cardinals shortstop -- who also happens to be a new teammate.
"I really wanted to talk to him and find out who he is and really find out about him," Aardsma said Wednesday. "I probably got a little out there before knowing somebody and judging somebody."
The Cardinals signed Aardsma to a minor league contract, hoping the veteran can fill the team's final bullpen spot.
Over the winter, St. Louis signed Peralta to a $53 million, four-year deal. The two-time All-Star became a free agent shortly after finishing a 50-game suspension in the Biogenesis scandal.
The Peralta pact prompted Aardsma to tweet: "Apparently getting suspended for PED's means you get a raise. What's stopping anyone from doing it?"
Aardsma walked back those words after talking with Peralta, saying the tweet was a knee-jerk reaction and that it's the job of the players' union to make the rules and judge the outcome.
"I'm not the judge, I'm not the jury and I shouldn't be the executioner, either," Aardsma said.
Despite having played against Peralta many times, Aardsma said the two had never spoken. He apologized to Peralta for tweeting without knowing him personally.
"(Peralta) seemed like he was very receptive and seemed like he listened and seemed like he had a great response," Aardsma said.
The Cardinals have spent much of spring searching for their final bullpen arm. The 32-year-old Aardsma likely leaps to the front of a list of candidates that includes Kevin Butler, Scott McGregor and Jorge Rondon.
"We bring guys in here with the purpose of making our team better and the only way we can see that is when they get on the mound and show what they have in comparison to others," Cardinals manager Mike Matheny said. "I'm anxious to watch him compete."
Matheny actually caught Aardsma during spring training when both were with the Giants in 2005. At that time Aardsma, a former first-round selection by the Giants, had a fastball that approached 100 mph.
"He's pitching more but he still has some good life on the ball," Matheny said.
Aardsma began the spring as a non-roster invitee with Cleveland, where he allowed two earned runs on five hits in six innings.
The right-hander didn't issue any walks with the Indians, but he walked the first batter he faced with the Cardinals on four pitches Wednesday. He also allowed a hit, but wound up working a scoreless inning against Washington.
"Obviously, walking the first guy like he did isn't part of the game plan, but it was nice to see him make pitches afterwards," Matheny said.
Aardsma is 23-15 with 69 saves and a 4.23 ERA during a seven-year major league career. He was 2-2 with a 4.31 ERA in 43 games for the Mets last year after missing almost two years because of injuries.