With the Cardinals leading the Mets, 6-3, in the fifth inning, Carlos Beltran stepped to the plate for New York. A runner stood on second base, and Beltran is just about the No. 1 Cardinal-killer in the National League. Todd Wellemeyer had reached his pitch count, and a reliever was needed.
Manager Tony La Russa called on McClellan, giving him arguably the biggest out of the game. And McClellan came through, catching Beltran watching a fastball for a called third strike.
"I love those situations," said McClellan, who had his parents and sister in the stands at Tradition Field. "You focus more."
McClellan followed his escape with two more outstanding innings. He finished with 2 1/3 shutout innings, allowing a double to Jose Reyes but no other baserunners. He struck out three as he continues to impress the St. Louis staff.
La Russa may have even unintentionally given a hint about just how good McClellan's standing is.
"I thought that was exactly the kind of situation that he's going to be challenged with," La Russa said, "and I thought he handled himself really well."
Shortly afterward, the manager made a similar statement, but made sure to add the critical if.
"It's indicative of the kind of situation he might be called upon to pitch in -- if he's on the club."
Yet everything adds up to McClellan making the team. The Cardinals have two open bullpen spots for four right-handers -- McClellan, Kelvin Jimenez, Cliff Politte and Chris Perez.
McClellan and Jimenez are both on the 40-man roster, while Politte and Perez are not. And McClellan could serve as a long reliever, something that both La Russa and pitching coach Dave Duncan have expressed a desire to have on the staff. None of the other pitchers profiles well as the "innings guy."
So while no one is declaring McClellan to be on the roster just yet, he keeps helping his case.
"I'm thrilled," he said. "If you had asked me coming in whether I would be here in the last week, I would have said I don't think there's a very good chance. But that's the thing about this game. You never know."
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.