Wide receiver Steve Smith, Manning's go-to guy on third down, was forced to leave practice on Thursday after hurting a pectoral muscle.
"He had trouble driving his arm after the injury, so he couldn't continue," Coughlin said. "I don't have anything to tell you about him until they do all of the tests."
Smith was not available in the locker room after practice. Manning also had not talked to Smith and was uncertain about his availability for the weekend.
Smith, who set a franchise single-season record with 107 catches last year, has made 47 for 517 yards and three touchdowns this season. He is second on the team behind Hakeem Nicks, who has 51, 653 and nine.
"We'll just stick to the gameplan until we hear otherwise," Nicks said.
Not having Smith would hurt though.
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"He's the most polished receiver we have," Gilbride said. "He's a guy who has really earned the respect of the defense to such a point that so many of the things they do are designed to stop him, and that's what has opened opportunities elsewhere."
"I think people, basically, have said it's hard to cover him one on one inside, so people have committed other people, additional resources," Gilbride said.
The outcome is the schemes have either opened up the Giants' running game or increased opportunities for the others.
In the win over Dallas, Nicks and Smith each caught nine passes for more than 100 yards. Nicks had two touchdowns and Smith one.
Manningham said if Smith can't go, the next guy in line has to be ready.
"Young players have to step up, me and Hakeem have to step up. It's time," Manningham said. "It's part of football. We also have do what we have to do and get a 'W' on Sunday. That's all that really matters. I feel we can put anybody in there, but Steve does certain stuff that other people can't do."
Smith is one of Manning's favorite targets on third down. He has 11 third-down catches for an average of 8.1 yards and two touchdowns.
Barden, the 6-foot-6 second-year receiver, has seen limited action in five games, catching two passes for 30 yards. Most of his plays have been on special teams.
"Week in, week out, I try to prepare like I am going to be an integral part of the offense," Barden said. "That's something I learned from him (Smith), Domenik (Hixon), and Hakeem. These are guys who are professional and approach the game in a most professional matter. Everybody has to step up. We will fill in. We have guys who can make plays."
Notes:Giants C Shaun O'Hara had no update on his sprained right foot. He did not practice and was wearing a boot. ... Twenty-three soldiers, wounded while serving, were guests of the Giants at practice on Veterans Day. The soldiers shook hands with the players after the workout and ate lunch with them in the team's cafeteria. "The message should go forth to all Americans that this is an opportunity for us to recognize our warriors, be it the wounded warriors or our veterans," Coughlin said. "From that standpoint, we need to take time, slow down and say thank you and make sure they realize how much they mean to all of us."
Copyright 2010 by The Associated Press