ST. LOUIS — St. Louis Rams running back Steven Jackson is optimistic he'll be able to play Sunday at New York against the Jets, but his coach needs to see evidence why.

Jackson did not practice Thursday for the second straight day. He'll try to give it a go on Friday as St. Louis (2-6) tries to snap a two-game losing streak.

"I am optimistic, very optimistic," Jackson said. "I'm hoping maybe even Saturday if I can during the walkthrough, have my own personal practice and see if I am able to burst."

But interim coach Jim Haslett says if Jackson can't practice on Friday, he won't play Sunday.

"We have to see full speed, hit the hole, running through the hole like he is 100 percent," Haslett said.

Jackson hurt his thigh in the Rams' 34-14 win over Dallas on Oct. 19. He missed the next game at New England and was ineffective, with just 17 yards on seven carries, in a 34-13 loss to Arizona last weekend.

Jackson wasn't sure he'd be able to show what Haslett hopes to see by Friday.

"You know, a full practice, probably not to be honest with you," Jackson said. "I'm surely hoping I come in tomorrow and something miraculous happens tonight and I can give a full practice like he's wanting."

An MRI on Monday showed inflammation remains in the injured area. But Jackson said it feels better.

"With a hamstring, quad or groin, those kinds of injuries, one day you feel great and the next day, the slightest movement or tweak can set you back," Jackson said. "That's just what I'm dealing with."

Haslett said the Rams will use Kenneth Darby and Samkon Gado if Jackson is unable to play. Antonio Pittman (hamstring) and Travis Minor (concussion) are both questionable.

"I think they're doing well," Haslett said. "We'll see in a game. They work hard. They're both smart guys. They run hard. I'm excited watching them work this week."

Darby was signed off the Falcons' practice squad Oct. 15 and likely will be the starter against the Jets. Gado, who was out of football before he was signed Tuesday, would be the backup and play on special teams.

Jackson said he's eager to help his replacements.

"The offense is really complicated. I'll do my best to help them. With a running back, once he knows where he's going, it's pretty much his own ability. I think they've done a pretty good job the last two days."

Quarterback Marc Bulger agreed.

"Whoever goes this week, we think we have capable guys," Bulger said. "We might have to simplify the game plan a little, but I think they are definitely capable."