The incumbent starting running back is Daryl Richardson, but he raised speculation over his role in the team when he told a fan on Twitter that he would not be starting this Sunday's match against the Jacksonville Jaguars.
However, Fisher stressed that they have not yet made their mind up on the issue, as well as hinting that he would speak to Richardson over his use of social media sites such as Twitter.
"I'll discuss it. I don't think he meant it. He's coming off some injuries and he just needs to be more thoughtful about his responses," Fisher told reporters.
"We haven't gone one direction or the other [on a starter] yet. We have just had one day of practice and all the backs got to participate in practice, so we've got different things for different style of runners."
The Rams rushed for just 18 yards on 19 carries last weekend, with Richardson currently leading the team in rushing this season with 114 yards.