St. Louis batters were visibly displeased with Barrett's strike zone, and a called strike on Jon Jay from Pittsburgh starter James McDonald prompted Oquendo's argument.
"The guys might've thought it was a little bit out of the strike zone," Oquendo said afterward. "We just wanted to make sure that when he throws, he throws it in the strike zone. If you started giving too far off the plate, it's hard for the hitter, for anybody. And we just wanted to keep the competition between the players."
Oquendo was ejected immediately as he made his way down the third-base line and approached home plate with the Cardinals trailing, 2-0. Oquendo kicked dirt on home plate and had to be restrained by manager Mike Matheny, who exited the dugout upon Oquendo's ejection.
"It's one of those instances where [Oquendo] went out defending me," Jay said. "That's part of the game."
Cardinals first-base coach Chris Maloney moved across the diamond to coach third, while bench coach Mike Aldrete replaced Maloney at first.
Matheny said he didn't want his hitters swinging at pitches they felt were out of the zone, but had been called strikes. Oquendo agreed.
"You hope you don't have to do that," Oquendo said. "A strike's a strike, a ball's a ball. That's what you want to call. I know [umpires] have a tough job to do. You just want to keep it at that. Call strikes, strikes and balls, balls. That's all."
Mike Still is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.