Manningham, who suffered a concussion last week against the Rams, told reporters on Monday afternoon that he was "good" and had passed his baseline test.
"Until I see it written down ... I am just waiting to see the official document from the medical people that he is ready to go," coach Tom Coughlin said.
Manningham missed the Giants' 29-16 win over the Eagles on Sunday. His status is still uncertain at the moment for this week's game against the Cardinals but the wide receiver believes he will be able to play.
"I'm good, I am going to be good," Manningham said.
Defensive end Justin Tuck may be limited this week in practice. Coughlin said the team's defensive captain has a strained groin to go with the troublesome pain in his neck.
" ... I think it is probably a strained groin that Justin Tuck had," Coughlin said. "We will see what that is."
Tuck aggravated his neck and briefly left Sunday's game before returning to play. Coughlin said the condition could continue to linger.
Tuck said on his weekly radio spot on WFAN that he was on his way to undergo an MRI on his neck but that the injury would not keep him from playing Sunday.
"A little bit of a recurrence of the same thing," Tuck said on WFAN. "I think a lot of teams know I have been having a little issue with it. I don't want to be Michael Vick here but they are kind of going at my head a little bit too. It is going to be something that we can battle through and it is something that I can battle through right now. As long as I can battle through it, I am going to continue to play and hopefully we can get it quieted down here."
"I'm playing," he added. "Barring anything in practice, it's a situation, it's football and it is a tough sport and you will have bruises and dings and pulls and it hurts. But I am not injured.
"Actually I am heading to get an MRI right now. I can definitely deal with it. I am not worried about getting there on Sunday. I don't see this being an issue where I won't play on Sunday."
Defensive end Osi Umenyiora ran on Monday morning, according to Coughlin. Umenyiora said last week he was hopeful that he could return to practice this week but said he wanted to be absolutely sure his knee is ready when he comes back. He underwent arthroscopic surgery on Aug. 19.
"It is the same kind of thing where you really are going to have to wait and see what happens," Coughlin said of Umenyiora's knee.
Manningham said he was experiencing sensitivity to light and that's why he was not cleared to play in Philadelphia.
"My eyes were hurting when I looked at the light," Manningham said.
"I like this (trio) better because simple fact is, not to throw nobody under the bus, he can go down field," Manningham said of Cruz. "Not saying Steve couldn't, but (Cruz) can go down field and make people miss instead of making people miss and then going down."
Cruz played at Manningham's "Z" spot but Coughlin said one of his touchdowns did come from him lining up in the slot. When Manningham returns, the Giants will still have to figure out who they want to play in the slot. Brandon Stokley also is an option there.
"That is something we are going to have to go through week by week," Cruz said when asked about Manningham and himself playing on the outside. "There is plenty of room for both of us to play and make plays and there is going to be plenty of opportunities throughout the course of the season."
After scoring on separate 74-yard and 28-yard touchdown catches, Cruz's confidence is starting to soar.
"The fashion in which Cruz came out of the game, that should be an adrenaline boost, that should be a confidence booster for him and his career," linebacker Mathias Kiwanuka said. "It was a big day for him on a day when we needed him to step up."
Ohm Youngmisuk covers the Giants for ESPNNewYork.com.