Alshon Jeffery is in jeopardy of missing his third consecutive game because of a hamstring injury.
The Bears' No. 1 receiver was limited in Thursday's practice. During the 15-minute portion open to media, he took part in some position drills and watched the rest.
"I mean, if I'm out there, no matter who's out there ... sky's the limit for this offense and this team," Jeffery said.
Jeffery said his left calf is "fine." That injury sidelined him for 27 days during the preseason. He returned in time to play against the Packers in the season opener, although he didn't appear fully healthy in catching five passes for 78 yards.
Five days later, he experienced tightness in one of his hamstrings after practice.
Suffering two muscular injuries in such proximity raises questions about whether he could aggravate the injuries or endure a new one if he returns to game action Sunday against the Raiders without fully participating in a practice.
"Man, it's kind of frustrating," he said. "At the same time it's a process. Time heals everything."
With Jeffery out of the lineup against the Cardinals and Seahawks, Eddie Royal has led the Bears' receivers in receptions (10) and yards (58).
And if Jeffery's and quarterback Jay Cutler's injuries weren't enough to contend with, left tackle Jermon Bushrod appears likely to sit out Sunday after he missed the last two practices with a shoulder injury and a concussion. He suffered both on the same play against the Seahawks.
Charles Leno replaced Bushrod for the final two quarters in Seattle, so he'd be positioned to start if Bushrod is ruled out. And if that happens, rookie tackle Tayo Fabuluje, a sixth-round pick, would likely be active for the first time.
Out of the club: Right tackle Kyle Long said he plans to play without the club he wore on his right hand for each of the last two games, calling it "water under the bridge."
He dislocated multiple fingers during the first quarter of the opener but finished that game, which was his debut at right tackle. He has played all of the Bears' 189 offensive snaps.
Extra points: The Bears hosted free-agent punters Spencer Lanning and Steve Weatherford for a tryout Thursday morning, two people with knowledge of the situation said. Punter Pat O'Donnell was limited in practice with a sprained right knee, which is his kicking leg. The Bears probably would wait until Saturday to sign O'Donnell's replacement, if necessary, giving him as much time to heal as possible. He punted 10 times in Sunday's loss. ... Defensive linemen Ego Ferguson (knee), Jeremiah Ratliff (left ankle) and Will Sutton (left elbow) were limited in Thursday's practice as was cornerback Alan Ball (groin). Ball was not listed on Wednesday's injury report, an indication his issue surfaced after Wednesday's practice.
Chicago Tribune's Brad Biggs and Dan Wiederer contributed.