Cowboys All-Pro guard Zack Martin says he's OK after sustaining a neck stinger in practice earlier this week.
But it's uncertain how many starting Dallas linemen will be available for a preseason game in San Francisco and that might influence quarterback Tony Romo's playing time.
Martin was injured Tuesday in the second of two joint practices with St. Louis at training camp. The second-year player shouldn't be out long.
The Cowboys are being cautious with left tackle Tyron Smith (right arm muscle strain), left guard Ron Leary (back) and right tackle Doug Free, who recently returned to practice after missing two weeks mostly to rest a sore foot and ankle.
If enough starters sit Sunday against the 49ers, Romo might join them.
"I think you certainly have to factor in what is going on with each player individually and figure out what the plan needs to be for that guy, and we certainly do that," coach Jason Garrett said Thursday. "We'll have a plan for those guys as to how much we want them to play or not play in a ballgame."
The Cowboys showed how much the camp roster is in flux with their busiest day of transactions Thursday.
Dallas signed receivers Phil Bates and Edmond Gates and linebacker Dakorey Johnson while waiving running back Lache Seastrunk, receivers Reggie Dunn and Deontay Greenberry and cornerback Brandon Smith. The club also claimed cornerback Rod Sweeting off waivers from Buffalo.
While the Cowboys' injury list has grown to more than 20 players in recent days, easily the scariest moment was Martin crumpling to the ground after throwing a block on a play in 11-on-11 work against the Rams.
Martin, the team's first rookie All-Pro since running back Calvin Hill in 1969, said his head was too low for the block, and it was the first time he had experienced a stinger. He was on the ground for several minutes while the medical staff attended to him before he walked off the field on his own.
"Just a little scare but everything's fine," Martin said. "Burning and then it shoots down your arms. When I got back to the locker room I felt fine."
Undrafted rookie La'el Collins, who was a projected first-round pick when his name surfaced in a police investigation over a woman's death and he wasn't cleared until after the draft, was already getting significant practice time because of Leary's injury. Martin's absence will put more focus on him.
"You can't ever have enough good football players," executive vice president of personnel Stephen Jones said. "You just never know where the injury bug's going to bite. One thing I'm starting to like about this team is I do think we have some depth."
But not enough to dismiss the idea of sitting Romo if most of his primary blockers skip the exhibition in San Francisco.
"Not going to be putting Tony in there with the wrong guys," Jones said. "It definitely impacts you. It's already started impacting. It impacts sometimes the periods you have in practice."