Giants coach Tom Coughlin had said that he thought Nicks would give it a go. Instead, Nicks, who missed Sunday's win over New England, tested his injured hamstring by running full speed on Wednesday. He also ran on it on Tuesday as well.
Nicks said he has suffered no setbacks so far and is feeling good.
"Ran and got up to full speed, felt good so we are going to stick with the plan, more and more each day and tomorrow I do a little bit more and no setbacks so that is a good sign," Nicks said. "If by the end of the week everything is still going good, then it is looking good for me. I am definitely happy, no setbacks, no pain afterward. It's looking good."
Nicks said he cut, ran straight and pretty much did everything while running and testing the injury. He hopes to do individual work on Thursday.
Bradshaw did not practice due to a fractured bone in his right foot. But Coughlin says the running back is improving.
"He's better than he was last week, that's for sure," Coughlin said. "Right now he is better than he was last week. He is walking around. He keeps getting better. We'll see. I'm just observing."
Bradshaw did not play against New England but likely will try to play with the broken bone in his foot -- something he did in 2009.
Center David Baas, who also missed last Sunday's game with a knee injury, went through a limited practice. Baas, who was sidelined by a knee injury, is working his way back to play against his former team in San Francisco.
The Giants are getting healthier, as defensive end Justin Tuck and running back Brandon Jacobs were not listed on the pre-practice injury report on Wednesday. Tuck has been nursing a strained groin and a neck injury, and this is the first time in the regular season that Tuck has not been listed with an injury.
Jacobs had a knee injury but appears to be over it as well.
Rookie wide receiver Jerrel Jernigan did not practice due to a hip injury.
Nicks' return would be a boost for the Giants, who are facing a Niners defense that is No. 1 against the run in the NFL but 22nd against the pass.
Nicks says he will be smart with his hamstring so that he does not suffer any setbacks. He says the biggest thing to look out for how the hamstring responds after work.
"That is going to be the question," Nicks said. "Going through practice and making sure it doesn't fatigue. When it gets fatigued, that is when you can injure it again."
Ohm Youngmisuk covers the Giants for ESPNNewYork.com.