The Falcons’ backups, who will fill in for four starters, will be on the hot seat against the Miami Dolphins.

Defensive end Jonathan Massaquoi will take over Kroy Biermann’s hybrid linebacker/defensive end role. Biermann was placed on injured reserve with a torn right Achilles tendon.

Linebacker Joplo Bartu, an undrafted rookie from Texas State, will take over for weakside linebacker Sean Weatherspoon, who’s out for eight weeks because of a foot injury.

Fullbacks Jason Snelling and Patrick DiMarco could split the fullback chores of Bradie Ewing, who was placed on injured reserve with a separated left shoulder.

Snelling and Jacquizz Rodgers will try to pick up the slack for running back Steven Jackson, who’s out with what the team believes is a short-term hamstring injury.

“People can expect me to play that role the same, if not the same, then greater,” said Massaquoi, a second-year player. “As the next man up, you have to keep the tempo and the pace almost as though no one has left.”

Massaquoi believes that he can help the Falcons’ anemic pass rush, which has registered two sacks, both by defensive tackles.

Bartu helped the Falcons slow tight ends Jimmy Graham of New Orleans (46 yards receiving) and Jared Cook of St. Louis (10 yards) in the first two games.

“Our coach emphasized re-routing them,” Bartu said. “We just try to put our hands on the tight end as early in the play and throw them off their timing.”