It took all of a few minutes for a significant injury to the Giants' secondary to dampen their first organized team activity of the offseason.

Cornerback Brian Witherspoon, coming off an ACL tear last August, was carted off the field after writhing in pain as trainers worked on him and his teammates knelt in prayer nearby.

And the Giants fear the worst.

"I'm afraid it was an ACL again," coach Tom Coughlin said after the session. He added that it's the same left ACL that Witherspoon tore on a punt return in a preseason game against the Bears last August.

Fellow cornerback Antuwan Molden, a free-agent signing this offseason, also was carted off later on. He pulled up lame in coverage with a hamstring injury and will be evaluated further by team doctors.

"It’s tough but I’ve been through this situation before so it’s good to know what to do," said the former Patriot, who has dealt with hamstring trouble in the past.

Undrafted out of Stillman College in 2008, Witherspoon has not appeared in a game since 2010 when he played in one for the Giants. Last season he was expected to contribute following an impressive training camp before he became one of the many Giants to succumb to significant injuries.

Those included fellow cornerbacks Terrell Thomas, who also suffered a torn ACL in that preseason game against the Bears, and Bruce Johnson, victim of a ruptured Achilles. Johnson participated in today's practice, but Thomas was held out. Afterwards, Thomas told reporters he is ahead of schedule and expects to be a "full-go" by training camp.

"It's just the way I feel," Thomas said. "It'll be around ten months at that time. The way my knee is feeling right now, I should be able to do everything by that time. Probably no contact, but I'll be able to do seven-on-seven, team and all that."

Jorge Castillo: jcastillo@starledger.com; twitter.com/jorgeccastillo