ALLEN PARK, Mich. -- One year ago, Wayne Gallman was the rookie running back added even though the Giants already had a youngster (Paul Perkins) at his position.

Now, the shoe is on the other foot for Gallman, who must figure out how to get his piece of the offense with rookie Saquon Barkley expected to commandeer close to 350 touches.

"That's my guy," Gallman said of Barkley, shutting down any thought of jealousy or bad blood. "You don't get drafted No. 2 for no reason. That's my boy, and we are going to work together."

Except right now Barkley might as well take out an Aflac policy because he is injured and can't work. Barkley suffered a mild left hamstring strain and is considered "day-to-day," though it is unlikely he sees live action at all this week as the Giants hold joint practices with the Lions.

The chain reaction means Gallman took first-team reps during Tuesday's practice. Gallman and 11-year veteran Jonathan Stewart are next up on the depth chart, but the Giants are careful not to wear out Stewart's 31-year-old legs in practice.

While head coach Pat Shurmur has to be holding his breath -- much like the fan base -- waiting for Barkley's return, it is an opportunity to see more of Gallman.

"I didn't know much about [Gallman], even though there were reps a year ago," Shurmur said. "I'm gaining an appreciation for what he is as a runner, a pass-catcher, and a blocker.

"Any of these young players that can get more reps than we had originally scheduled for them, that's a blessing for those guys because they have the opportunity to show us more of what they can do, and improve. When you're young and fresh-legged, you have an opportunity."

It turns out Gallman's best bet for getting the football might be by catching it. As a fourth-round pick in 2017, Gallman averaged 4.3 yards per carry and finished with 476 yards on the ground. He also made 34 catches for 197 yards and one touchdown.

But Gallman never looked completely comfortable running routes out of the backfield.

That perception has changed this offseason -- perhaps he saw Shurmur's comments at the NFL Combine about not having a use for running backs who can't catch. Gallman has been a weapon on screens.

Is he a much better receiver than he was a rookie?

"I think I am," Gallman said, "in terms of confidence and knowing what the quarterbacks want."

Gallman had the most targets (six) and the most receptions (four) in the preseason opener against the Browns. He also played the most snaps (24).

"I put in a lot of work in everything," Gallman said. "I think we have a pretty balanced offense."

Ryan Dunleavy may be reached at rdunleavy@njadvancemedia.com. Follow him on Twitter @rydunleavy. Find our Giants coverage on Facebook.