Speaking on ESPN 1050's Michael Kay Show, Manning said he passed all tests administered at the Hospital for Special Surgery in New York on Tuesday.
"It feels really good," Manning said. "I was a little worried last night, but no headache, there was no concussion of any sort. ... My body, my mind, my head all feels really good. It's just a matter of getting back, just a matter of when I can put a helmet on, all the stitches, get those taken out and get cleared to play.
"All day, I've been getting tests done, just making sure there's no further damage to my brain or to my skull and stuff, and everything looks fine, so that's good news."
"They haven't given me an exact timeframe of when I will be back, but I have a feeling I might be out this upcoming week just trying to get these stitches healed up and my forehead healed," Manning said. "I don't know when I will be able to put a helmet on. Hopefully I'll be able to rig something up. I might have to bring out an old leather helmet to get some practice in this week because I don't want to be sitting around doing nothing when I feel I can play. The helmet might be the only restriction right now."
Manning was hurt with 10:45 left in the second quarter of Monday night's preseason game, when he opted to throw a pass on a run call without telling the rest of the offense.
Expecting a handoff, Giants running back Brandon Jacobs crashed into Manning with his shoulder as the quarterback pulled the ball away. The collision knocked the ball loose and pushed Manning's chin strap off his jaw. Then Jets linebacker Calvin Pace hit Manning in the middle of his back, knocking off his helmet and pushing his face first forward.
"It's my fault," Manning said. "They had a run play called. I should have checked to the pass play. I kind of called the receivers just to run fades, thinking we do that some times. Certain runs, you can just get up and throw it real quick, but on that certain play ... you had Brandon coming right up the middle. A quick-hitting play, and I just kind of forgot he might be coming right up the middle and I might run into him on my dropback. And, sure enough, that's what happened."
With his helmet off, Manning's head slammed into Leonhard. Manning immediately fell to the turf and put his hand to his head. He quickly motioned to the Giants' training staff for help once he saw his hand covered in blood.
"I probably did panic just a little bit because I kind of saw it gushing out and put my hand on it, all over my hand, all over the place," Manning said. "When you see that much blood, you do panic a little bit. But again, I kind of knelt down for a second because I didn't know what was going on, but I felt like I could stand up, met the trainers half way, and they covered it up, put some pressure on it."
Manning said he felt well enough upon returning home that he was able to watch highlights of the game. He liked what he saw out of Cruz.
"He's done a great job, he's earned some playing time, definitely, with the ones probably," Manning said of the receiver out of Massachusetts. "He made some great catches. ... All his plays were impressive, even the ones that weren't touchdowns.
"He's worked hard, he's stayed healthy. He's smart, he know what's going on. He's done a good job studying the gameplan, and he's really made great strides over training camp."
The Associated Press contributed to this report.