Marshall wasn't available for comment Wednesday.
Miami also has a quarterback question because Sparano hasn't named a starter. Tyler Thigpen and Chad Henne took snaps with the first team Wednesday.
Those are two major issues for a 5-5 Dolphins team that probably must win its remaining six games to have an outside shot at a playoff berth.
Marshall, the Dolphins' big offensive free-agent acquisition, is seventh in the NFL in receptions and 16th in receiving yards. He has 58 receptions for 693 yards and one touchdown this season.
"With Brandon being out, I think that's going to leave a lot more 1-on-1 matchups that we're going to have to win," he said.
Thigpen was the Dolphins' third-string quarterback two weeks ago, but injuries to Henne (knee) and Chad Pennington (shoulder) made Thigpen a starter in last week's 16-0 loss to the Chicago Bears. But Thigpen threw two interceptions against the Bears, and Henne is on the mend, so the starting job is up for grabs.
"I feel pretty good," said Henne, who suffered his injury during a 29-17 victory over the Tennessee Titans on Nov. 14. "I've been rehabbing, and it's been going better each and everyday. I haven't had any setbacks. Right now, I don't know where it is, but I'm practicing and it's getting better."
There has been other good news related to the Dolphins' injuries. Center Joe Berger, who missed the Chicago game with a knee injury, returned to practice. That means right guard Richie Incognito can stay put this week. Left tackle Jake Long (left shoulder), who wears a protective harness, practiced, and it appears that he'll start Sunday.
Miami had given up just 12 sacks heading into the Chicago game, then surrendered six sacks to the Bears.
Copyright 2010 by The Associated Press