Mike Tomlin said rookie halfback Le'Veon Bell looks ready to play his first game and might start Sunday against the Minnesota Vikings in London.

Pardon quarterback Ben Roethlisberger if he does not get too excited about the news.

"We are excited about watching him be a full participant this week during the course of practice" Tomlin said. "We will let that dictate his play but we are optimistic about his availability."

Bell has not played since he left the second preseason game with a small tear of a ligament in his right foot. The Steelers drafted him in the second round and were preparing him to be their starting halfback. Tomlin said Bell "perked up dramatically" in practice last week although he was inactive for his third consecutive game Sunday night.

Roethlisberger was skeptical when he talked about Bell's prospects of playing on his show Tuesday on 93.7 The Fan.

"Honestly I have no idea with him" Roethlisberger said. "You can't get a read on him. One day he's practicing one day he's not; one day he's going hard the next day he's not. I wish I could.

"If he was a guy like Heath Miller that you knew was busting his butt every day to get back there ... Le'Veon is a rookie I don't know him quite well enough yet. But if he can come back and help us we'll take him."

The Steelers drafted Bell from Michigan State to improve a running game that sunk to 26th in the NFL last season and lost former first-rounder Rashard Mendenhall in free agency. Bell played 40 games in his three seasons at Michigan State where he ran for 1740 yards in 13 games in 2012.

Yet that durability has not transferred to the pros.

He bruised a knee in training camp that kept him out of the first preseason game and after running four times for 9 yards in the first series of the second preseason game at the Washington Redskins Bell left with his midfoot sprain.

There is little question that he is the most-talented back the Steelers have.

Todd Haley compared him to Eddie George after the draft and the coordinator acknowledged in August that Bell's running style reminded him of Franco Harris.

Bell is 6 feet 1 244 pounds.

"He's not a guy that you'd shy away from giving it to him 30 times a game" Haley said in the spring.

Without Bell -- they also lost veteran LaRod Stephens-Howling to an ACL tear in the opener -- the Steelers have had little success running the ball.

They were next-to-last in the NFL after two games with 76 yards rushing. They more than doubled that with 80 yards Monday night against Chicago but they still rank 31st and have been juggling backs through three games.

Isaac Redman started the opener and was scheduled to start the second game until he was hurt on the opening kickoff.

Felix Jones then started the second game and leaped over Redman by starting again against the Bears.

The second back in was Jonathan Dwyer who was cut and re-signed after the opener.

Jones leads them with 71 yards rushing and a 4.2-yard average per carry.

As for how much Bell might play in London Tomlin said "We'll let the practice process be our guide in terms of deciding how much work he gets in the football game."