Shaw was reinstated Tuesday after missing 10 games.
"I thought he moved pretty fluidly," Sarkisian said. "You can tell he's been active.
"From a game-plan standpoint, we really don't know."
Shaw is no longer a captain and Sarkisian said the senior would not be accessible to the media until a bowl game.
"I just want to give him a chance to focus on playing football," Sarkisian said. "He's been through a lot and probably gotten more media attention than he's ever wanted over the last three months."
Shaw was suspended in August after admitting he fabricated a story about how he injured his ankles. He also was the subject of a police investigation related to an argument he had with his girlfriend, but he was not charged.
USC players welcomed him back.
"People make mistakes," linebacker Su'a Cravens said, adding, "That's our brother. We're always going to have his back."
Said defensive lineman Leonard Williams: "It's just great to have him back. He's a great player."
Defensive coordinator Justin Wilcox said there was no time line for when Shaw might play.
"We're glad to have Josh back," he said, adding, "We'll see."
Secondary coach Keith Heyward echoed Wilcox.
"Having Josh back is a bonus," he said. "How he's going to help us, if he's going to help us, I don't know."
Heyward said he saw enough of Shaw during training camp to assess his talent.