The status of Derek Cox remains uncertain.

Cox, the Jaguars' starting right cornerback, likely will be a game-day decision this weekend, Jaguars Head Coach Mike Mularkey said Friday, the same day five other players were officially ruled out for Sunday's game against Detroit.

Among those players:

Starting left cornerback Rashean Mathis, who will miss a second consecutive game with a groin injury and whose absence leaves the cornerback situation uncertain for a second consecutive week.

Cox was listed as questionable on the team's injury report Friday, and Mularkey was asked afterward if he was concerned having Mathis out and Cox uncertain against the Lions and All-Pro wide receiver Calvin Johnson.

"It's always a concern at that position," Mularkey said as the Jaguars (1-6) prepared to play the Lions (3-4) at EverBank Field Sunday at 1 p.m.

Cox, who has missed three of seven games this season, worked on a limited basis Friday after missing practice Wednesday and Thursday with a back injury.

"You would like to play on Sundays," Cox said. "I would like to play."

Mularkey said the decision on Cox will be made at least in part on how he feels Saturday.

"We'll monitor how he feels after a day and see how he feels in the morning," Mularkey said.

In addition to Mathis, the Jaguars also on Friday ruled out fullback Greg Jones (hip), fullback Montell Owens (shoulder), running back Maurice Jones-Drew (foot) and safety Dwight Lowery (ankle).

Jones-Drew and Lowery had been ruled out early this week, with Rashad Jennings expected to start a second consecutive game for Jones-Drew and Chris Prosinski expected to start a third consecutive game for Lowery.

Center Brad Meester (foot), quarterback Blaine Gabbert (left shoulder) and wide receiver Laurent Robinson (concussion) were listed as probable.

Robinson worked full all week, and he and Mularkey each said Friday he likely will play Sunday.

"He'll be up," Mularkey said.

Robinson, who said early in the week he wanted to get back into playing shape after missing three games with his third concussion this season, said the week went well.

"I was just getting back into the routine of catching the ball, cutting, getting tired out there," he said. "It felt good to be back out there. I want to get through a game, get hit a couple of times and see how I respond to that."

The Jaguars made multiple roster moves last weekend to manage positions because of injuries. Mularkey said Friday it was too early to know if there would be similar moves this weekend. He also said Friday's practice finished well after starting slow.

"When the buzzards started circling us, I thought that may be a good sign to call them up," Mularkey said. "It was quiet, and I said, 'We've got to get some energy.' They responded, and really had a very good practice."

Mularkey also said while the team will change a few signals because of the presence of Mike Thomas on the Detroit roster, he said the changes will be minor. The Jaguars traded the veteran wide receiver to Detroit Tuesday.

"It's really some very simple things," Mularkey said. "Even if we don't have a player on the other team we change up every so often."