WASHINGTON -- A day after the Cardinals acknowledged that Joel Pineiro will not be activated from the disabled list to start on Thursday, it's becoming clearer that they may be without the right-hander for more than just his next start.

Pineiro, who stayed back in St. Louis rather than accompany his teammates to Washington, has not pitched since May 20. He sustained a right groin strain the day after that game and has not been able to throw even a normal-effort bullpen session since then.

"He still isn't able to throw a full bullpen without some kind of issue," manager Tony La Russa said.

Rookie Mike Parisi will make a second start in Pineiro's stead on Thursday, and the next turn in the rotation could come in the Cardinals' series next week in Cincinnati. However, the club does have the benefit of an off-day on Monday, meaning that the other four starters could simply push up to a normal four days' rest. In such a scenario, the next time the Cardinals would need a fifth starter would be Saturday, June 14.

Until Pineiro can throw off a mound at a normal intensity level, there is no way of knowing whether he would be available that day, sooner, or later. For the time being, Parisi will hold the spot down despite a rocky first big league start.

"It's an opportunity for Mike," La Russa said. "If he has a couple games like the first one, then somebody else gets the ball."