A source said Nicks' MRI did not show anything serious and that the wideout is "all good." Nicks' status for practice and next Monday's game against the Rams will be updated later this week by the Giants.
Coach Tom Coughlin would not speculate beforehand as to what the injury is but the injury-ravaged Giants cannot afford to lose their top offensive playmaker.
Nicks underwent X-rays on his wrist and knee following the Giants' 28-14 loss in the season opener to Washington on Sunday. The X-rays were negative.
Nicks had seven receptions for 122 yards against the Redskins, including a 68-yard catch.
When asked for more details on what the injury to his knee is, Coughlin said: "I don't know the answer to that. They are checking all that out."
"Just the fact that it was swollen today," he added as to why there is concern.
On Sunday night after the game, when asked about his legs, Nicks replied, "Yeah, they're good."
When it comes to knees, the Giants have had awful luck this season. Cornerbacks Terrell Thomas and Brian Witherspoon, along with linebackers Jonathan Goff and Clint Sintim, all suffered season-ending torn ACL injuries.
"I hope (Nicks) is OK," quarterback Eli Manning said in his weekly interview on ESPN New York 1050. "I talked to him a little bit today. We definitely need all of our firepower and all of our weapons right now. Especially Hakeem, had a big game yesterday. He and Mario Manningham are our studs and we need that third guy whether (Domenik) Hixon or Victor Cruz gives quality play for us."
Also, Coughlin was not sure if defensive end Justin Tuck would practice this week after missing the opener with a sore neck.
Ohm Youngmisuk covers the Giants for ESPNNewYork.com.