Marshall's passing numbers have only been decent, with six touchdowns against four interceptions.
Malzahn said Tuesday he's "day to day" for the game with a right, throwing shoulder injury but the quarterback did practice Sunday.
Marshall is a key part of the nation's fifth-best ground game, with 461 yards and five touchdowns despite missing all of one game and most of another with injuries.
"They're No. 1 in the SEC in rushing the football," Bielema said. "He's a valuable part of that, whether it's a read-zone or a quarterback run game or he makes the right call on where the ball needs to be handed off. And he's very efficient. I think he's gotten better every game. You can see him gaining confidence. That (Texas) A&M game, they were must matching them score for score. That was a pretty impressive game to watch."
Marshall has plenty of help in the running game.
Tre Mason (753 yards, nine touchdowns), Artis-Payne (510, five) and Grant (451, four) have all played significant roles in the rushing attack. All four of those players, Marshall included, have produced 100-yard games. Only five teams have had four players reach triple digits in a game this season, including Ohio State, Air Force, Minnesota and Arkansas State.
The Tigers have had a pair of 400-yard rushing games for the first time since the Bo Jackson-led 1985 team.
"It's actually fun, getting in, with the o-line we have and the receivers we have," Grant said. "I can just break one at any time."
The offensive renaissance is not just about Marshall and the running backs.
Sammie Coates 25.5-yard average on 21 catches leads the nation. And the offensive line led by center Reese Dismukes and left tackle Greg Robinson has given up only seven sacks, tied with Alabama for second-best in the league behind Arkansas.