Browns head coach Pat Shurmur wouldn't say how long Hardesty will be sidelined, but did say he would miss "some time."
"Hardesty pulled a calf," Shurmur said. "He's in a boot and is going to miss some time."
Shurmur was asked if Hardesty will miss any games.
"It's very doubtful he'll play this week," Shurmur said. "It will take some time to heal up."
Hardesty was injured in the first quarter after two carries for six yards. Hardesty missed the entire 2010 season with a torn ACL. Hardesty leads the Browns with 75 rushes for 244 yards (3.3 avg.) with no touchdowns. He's caught 12 passes 113 yards.
The injury left the Browns with one healthy running back in Chris Ogbonnaya. Peyton Hillis sat out the second consecutive game with a hamstring injury. Ogbonnaya has 14 rushes for 52 yards, including 11 for 37 against on Sunday. Ogbonnaya caught 10 passes for 67 yards in the two games he's been with the Browns. Hillis has 60 carries for 211 yards (3.5 avg.) and two touchdowns in four games. He has 15 receptions for 76 yards.
Shurmur said the Browns will be auditioning backs on Tuesday.
Rookie Armond Smith, who was on the active roster and now is on the practice squad is a possibility.
Shurmur indicated he'd prefer a back that has experience and can step in and play, as soon as this week.
"We'd like to have a guy who can be up and running quickly," he said.
After missing the last two weeks, the Browns would get a big boost if Hillis would be able to play this week.
"We're hopeful," Shurmur said. "He's day-to-day."
Hillis practiced last Wednesday and was sore the following day resulting in the setback.
It is obvious the lack of a rushing attack has seriously hurt the Browns in all phases of their offense. However, Shurmur wouldn't use the injuries to the running backs as an excuse.
"Our list of runners has increased, but I like to think we can still run the ball," he said. "We've sustained some injuries, but we just have to keep playing. Once you make the first excuse, it's a slippery slope. There are no excuses."
On the season, the Browns are averaging 3.2 yards a carry and have only scored two rushing touchdowns.
Injury Update: Besides Hardesty and Hillis those listed on the injury report are DL Auston English (knee), WR Mohamed Massaquoi (concussion), LB Chris Gocong (stinger), DB Dimitri Patterson (knee) and DB Ray Ventrone (hamstring).
Shurmur said Massaquoi was doing light running and making progress. English is progressing, but it likely out for this week's game. He said Patterson had an MRI on his left knee, but no results were back. Ventrone did some running and is doing well.
Shurmur was asked if Gocong suffered the same injury that was termed a ‘stinger' that kept him out the entire preseason.
"I don't know that specifically," he said. "I heard he was feeling better today."
Defense Drops: The Browns defense dropped from fourth to sixth in the NFL. The Browns are 26th in rushing defense and second against the pass. On offense, the Browns are 25th overall, 29th rushing and 20th passing.
The 49ers rushed for 174 yards on 39 carries for a 4.5 average. Frank Gore had 134 yards on 31 carries. The Browns travel to Houston to take on running back Arian Foster and the Texans' fourth-best rushing offense.
"The defense battled in the first half and (the game) could've got out of reach," Shurmur said. "They battled in the second half and found a way to keep (the 49ers) off the boards."
Norwood Shines: Shurmur called wide receiver Jordan Norwood a bright spot in the 20-10 loss. He caught five passes for 32 yards in his most extensive playing time.
"Norwood stepped up and made some plays," Shurmur said.
Shurmur was asked if he still feels he has enough playmakers.
"We're putting the guys out there who can make plays," he said. "Jordan Norwood is new to the party and he had some production. Greg Little had some production."