SANTA CLARA – Nate Clements, who pulled double duty as a cornerback and punt returner against Buffalo, could be limited in both regards Sunday against the Jets.

Coach Mike Singletary revealed Wednesday that Clements suffered a small fracture in his left thumb against the Bills. He sat out practice Wednesday, the first practice Clements has missed since joining the 49ers last year.

The 49ers have been criticized for not playing enough press coverage this year, and a thumb injury promises to make jamming receivers more difficult. Singletary said the team would be cautious with its top cornerback this week.

"We just have to see how it goes – the pain tolerance and all of the other things," he said. "How much damage (will it cause) if he does anything? How much will it affect him later? So we have to think about all of those things."

The injury also creates a dilemma at punt returner.

Singletary initially didn't want to use Clements in that capacity against the Bills for fear of injury. Before the game, however, special-teams coach Al Everest impressed upon Singletary the importance of having a return man with experience, especially in the rain and wind of Orchard Park, N.Y.

With Clements ailing, the 49ers could be even thinner at the position this week. The primary return man, Allen Rossum, did not practice Wednesday because of the ankle injury that kept him out of last Sunday's game. Another potential returner, Arnaz Battle, was limited in practice with a foot injury, but his status for Sunday is questionable.

Singletary said that fullback Michael Robinson or even veteran receiver Isaac Bruce could be called upon to handle punts Sunday.

Robinson has no NFL experience as a punt returner. Bruce, meanwhile, is credited with one punt return, which occurred in his second season with the Rams in 1995. However, the ball actually was fielded by teammate Todd Kinchen, who tossed it backward to Bruce, who returned it 52 yards.

Cross words – Singletary on Wednesday was asked about the large wooden cross he wears around his neck at practice and on game days.

The coach said he came upon the cross in Green Lake, Wis., where he and his family vacation every year.

"It's a little Baptist grounds, and we get together with about 50 or 60 family members and just have a blast," he said.

Singletary said that God is the "number one thing in my life" and that he wears the cross "as a reminder of who I am and not lose my mind on the field and not become somebody else."

He said he hasn't asked the league – rigid when it comes to sideline apparel – for permission to wear the cross. But he said it wouldn't be a problem if he were asked to take it off.

"If they say something about it, I would just move on," Singletary said. "It's not that big of an issue. It's more in me than on me."

Et cetera – The 49ers added linebacker Justin Roland, an undrafted rookie out of Kansas State, to their practice squad. The team had wanted to add receiver Chris Hannon to the practice squad as well, but he was claimed by the Miami Dolphins instead.

• Safety Dashon Goldson and receiver Josh Morgan returned to practice on a limited basis. Goldson has missed the last five games with a knee injury; Morgan has missed the last three with a groin injury.

• The 49ers will honor former defensive end Fred Dean at halftime of Sunday's game by presenting him with his Pro Football Hall of Fame ring.

Read Matthew Barrows' 49ers blog at www.sacbee.com/ninersblog.