TONIGHT’S GAME : PITTSBURGH STEELERS AT MIAMI DOLPHINS CHANNEL 7, 6 P.M.

It is a matchup of the Dolphins’ league-leading offense (364.3 yards per game) against the Steelers’ league-leading defense (261.4).

Usually the defenses win these kinds of matchups.

But Pittsburgh has to prepare for two very different quarterbacks: young left-hander Scott Mitchell and veteran right-hander Steve DeBerg.

Mitchell has recovered from a dislocated shoulder. But if he isn’t ready to go, DeBerg is more than a solid replacement. The Dolphins’ 19-14 loss last week to the Giants was DeBerg’s first defeat since replacing Mitchell. In his three games, DeBerg has been best in the the fourth quarter, completing 32 of 48 passes for for 400 yards and three touchdowns.

“If Mitchell is 100%, then in all likelihood I would start him,” Dolphin Coach Don Shula said. “If he’s less than 100% in any way, I would start DeBerg. DeBerg has done an extraordinary job in the month he’s been with us.”

Mitchell’s status was upgraded from questionable to probable.

“It appears he’s throwing the ball with good velocity,” Shula said. “He has to build his strength back up and get his timing down. It doesn’t happen in one day.”

The Steelers are hoping that running back Barry Foster will be ready to play after suffering a severely sprained ankle three weeks ago. Foster practiced Wednesday, but is still listed as questionable.

Pittsburgh’s Neil O’Donnell, who had tendinitis in his elbow early in the season and a severely bruised shoulder from a late hit two weeks ago, will have to play better than he did last week for the Steelers to win. He completed 17 of 32 passes for 115 yards--but had minus-five yards passing in the second half against the Patriots.