Pittsburgh Steelers star Le'Veon Bell didn't attempt to run on Thursday as he still feels uncomfortable testing his injured knee.

The Steelers running back suffered a hyper-extended knee but he insisted on Wednesday that it "felt great". However, he will have to prove his fitness in an extra practice on Friday.

Coach Mike Tomlin is hopeful that Bell can feature in practice, but offensive co-ordinator Todd Haley has revealed that he would be comfortable playing the 22-year-old if he passes a fitness test on Saturday.

Teammate Antonio Brown told NFL Media that he is confident that Bell will suit up as "it's a really big game" against the Baltimore Ravens.

If Bell fails to pass his fitness test, the Steelers are preparing undrafted rookie Josh Harris to start in his place.