The Pittsburgh Penguins' slow start cost Mike Johnston his job.

The Penguins fired Johnston and assistant Gary Agnew on Saturday morning with the high-profile team languishing in the middle of the pack in the crowded Metropolitan Division.

Mike Sullivan, who was head coach of the Boston Bruins from 2003-06 and was serving as the coach of Pittsburgh's affiliate in the American Hockey League, replaces Johnston.

General manager Jim Rutherford said in a statement the Penguins and their star-filled roster that includes former MVPs Sidney Crosby and Evgeni Malkin have underachieved.

Pittsburgh, which lost to Los Angeles in a shootout on Friday night, is 15-10-3 and in fifth place in the Metropolitan entering Saturday. The Penguins are 28th in scoring.

Johnston went 58-37-15 during his brief stint with Pittsburgh.