San Francisco linebacker Dan Skuta looked good playing table tennis Friday despite a bone bruise in his left ankle.

However, he was limited in practice and is questionable for the game with the New York Giants on Sunday.

"Sunday is realistic," the sixth-year veteran said. "I went pretty hard today. I'll have to see how it feels tomorrow."

Skuta is one of several linebackers who have missed time for the 49ers this season, a list that includes all-Pro Patrick Willis, NaVarro Bowman and Aldon Smith.

Smith returns against the Giants from his nine-game suspension for violations of the NFL's substance-abuse and personal-conduct policies.

"He's looked good all week," 49ers coach Jim Harbaugh said. "He's had a bounce in his step and looks like he's enjoying it. As you're thrown back into action, the biggest thing is that the instincts get honed, the reflexes are honed."

Willis learned he needed surgery on his toe and will miss the rest of the season. Bowman has yet to play because of a knee injury and must practice by Tuesday to be eligible this year.

Harbaugh deflected questions regarding the results of Bowman's MRI and what it may mean for his future.

Skuta missed the first football game of his career and called it the most frustrating thing in his life.

"I don't know what to do pacing the sideline," he said. "It's still day to day, but it's getting better. It's been 12 days and I was told the timetable for something like this was two or three weeks."

Skuta said he was harder on his ankle than if he participated in the full practice. He went through hard cutting drills and is anxious to see how it reacts Saturday.

He considers playing table tennis part of the healing process.

"It's good rehab because I'm taking little hops to get going like I would just before a play," Skuta said.

Rookie linebacker Chris Borland, who has been a pleasant surprise filling in for Willis, was limited for Wednesday's practice because of a shoulder problem. He was careful in the full practice the next two days.

"A very talented player. Means a lot to him. Gives great effort," Harbaugh said. "Very smart and executes all his assignments, as he did in college."

NOTES: S Jimmie Ward (foot) and DT Ian Williams (fibula) are out while Skuta, CB Tramaine Brock (hamstring) and WR Bruce Ellington (ankle) are questionable. . In addition to Borland, RB Frank Gore (hip), DE Ray McDonald (knee), S Eric Reid (ankle) and DE Justin Smith (non-injury related) are all listed as probable.