The 34-year-old cornerback was still feeling the effects of his first practice with his new teammates.
"Just to be out there on the field with the guys and running around and they throw you right in there, it's really a test to see if you're an old man or not," Law said with a laugh. "I didn't let them see it, but I feel kind of old."
Law signed with the Jets on Tuesday and practiced with the team after sitting out nearly 11 months as a free agent. The Jets only had a walkthrough Wednesday, so Law is trying to get up to speed quickly, with hopes of playing Thursday night against New England.
"I must admit, it was OK, and I was a little rusty, but I expected that going in," said Law, who also played with the Jets in 2005. "It was nothing more or nothing less than what I expected to feel when I went out there. I was feeling a little awkward at times because I'm used to working out and training on my own. It's different going against air and going against somebody. I did have fun, though."
Law, whose last NFL game came in December against the Jets while with the Kansas City Chiefs, got a passing grade from coach Eric Mangini.
"He looked spry," Mangini said. "He got a decent amount of reps and didn't seem to be too winded. ... Considering where he's starting from, he looked very good."
When told of his coach's comments, Law smiled and then asked for the exact definition of "spry" before continuing.
"Yeah, I was energetic," he said with a laugh. "I was a little rusty, but it felt good just to be back out there with the guys, the camaraderie, and it'll just come with time. I had to do a lot. I worked in the rotation but also did all the scout team reps just to get myself going."
Law is expected to be more of a role player at the cornerback and safety positions, at least for now, and said regaining his footwork will be his biggest challenge. He kept up his workout and conditioning routines during the last several months just in case the right opportunity came up.
"I got the itch, got the bug," he said. "I wanted to play bad. On Sundays, I went out there and simulated my own little football games in the morning and then I'd come watch football."
Law, who has 52 career interceptions, said this comeback is about much more than collecting another paycheck.
"Everybody thinks it's money, money, money," he said. "New England offered me more money than I'm getting paid here. New England offered me a good bit more, but I felt like this was the right situation and Eric was always forthright with me about how he was going to utilize me and let me come in and play. If I want to play beyond this season, I think this is the best chance to do so and the best chance to win, in my opinion."
After seeing what Brett Favre has done with the Jets, Law was convinced he needed to be back on the field.
"He was part of my motivation," Law said. "I use guys like Brett and guys like Bernard Hopkins. I'm sitting there like, 'If these guys can go out there at 43 years old and knock out a 26-year-old guy, and Brett can still sling that thing at 45 or whatever he is -- 50 -- I know I can still go out there and cover somebody.' I always believe in myself, no matter what anybody else believes."
Law spent his first 10 seasons with the Patriots, with Mangini as his defensive backs coach for four of them. He realizes his signing adds a little extra juice to an already juicy matchup.
"It's just that I'd been there so long and I had a lot of success with the Patriots," Law said. "You can't ask for anything more. You're on prime time, you're playing the great New England Patriots. They went undefeated last year and I've been a part of that organization for a long time and had a lot of success. I have three Super Bowl rings, so the drama continues with both of these teams."
Law thinks this group of Jets can break the stranglehold the Patriots have had on the AFC East for so long.
"I'm definitely biased toward the Jets anyway, but the steps these guys have taken is definitely in the right direction," he said. "They have momentum right now and have a lot to play for, so this game is going to tell a lot under the lights against a divisional rival that normally gets the best of them. I'm just here to lend a helping hand."