Callahan was expected to miss 4-6 weeks after spraining his left knee against the Nashville Predators on Dec. 10, but he said he does not feel any lingering effects from the injury and is prepared to play Friday.
"I think it's hard to tell [how long it will take to recover] when it's that far out, but rehab went how it's supposed to. I don't think it's too far ahead of schedule," Callahan said. "It's hard to sit out and watch your team, and I say this every time, you're working to get back out there with the guys and it doesn't matter how many times or how many games you've played, when you've been hurt, you've been rehabbing and you get a chance to come back you're happy to get back out there."
With Callahan back in the lineup, the Rangers are fully healthy. The same cannot be said for Pittsburgh.
Since Pittsburgh's last home game, a 4-3 win against the Calgary Flames on Dec. 21, defensemen Brooks Orpik and Rob Scuderi have returned to its lineup while forwards Pascal Dupuis (knee) and Chris Conner (hand) have been sidelined.
Dupuis' season-ending knee injury has created a hole on the Penguins' top line next to Sidney Crosby and Chris Kunitz. Joe Vitale played with Crosby and Kunitz in recent games but will be replaced by James Neal on the top line against New York.
Neal most likely will remain in that position for at least the duration of forward Evgeni Malkin's recovery from a lower-body injury. Malkin and defenseman Kris Letang (upper body) practiced Thursday, but neither will return against New York.
The addition of former Rangers forward Taylor Pyatt, who will make his Penguins debut against his former team a day after he was acquired off waivers, will be the most noticeable change to Pittsburgh’s bottom-six forward group.
"It's definitely a little strange playing the old team right off the bat," Pyatt said. "It's a new opportunity, a fresh start."
Here are the expected lineups for the Penguins and Rangers:
Scratched: Deryk Engelland
Injured: Evgeni Malkin (lower body), Kris Letang (upper body), Andrew Ebbett (ankle), Beau Bennett (wrist), Paul Martin (leg), Chris Conner (hand), Pascal Dupuis (knee), Jayson Megna (lower body), Tomas Vokoun (pelvis)