General manager Peter Chiarelli announced Friday that Lewis will be relieved as head coach and reassigned to another position in the organization. Associate coach Marc Habscheid also will be reassigned.
"I have great respect for both of those men and what they've done in the past and what I think they will accomplish in the future," Chiarelli said on a conference call with reporters.
A lack of consistent play throughout the entire season was a key factor in the decision to remove both coaches from their positions.
"You see a level of play that you expect and want and it teases you, and obviously something wasn't getting through," Chiarelli said. The general manager said he doesn't expect "top level play" all the time, but insists the team be more consistent on the ice.
The Bruins flirted with the playoff race for a while but went 1-10-1 in their last 12 games and played shoddy defence, allowing 289 goals - the second most in the league.
Boston also was short on offence with 217 goals, seventh fewest in the league.
Lewis was 35-41-6 in his lone season on the Bruins' bench. He also was the head coach in Detroit from 2002-04, where he had a 96-41-21-6 record.
"As a coach, you go into a new organization not really sure what you have and not sure what you need. By the end of the year, I knew what we had and I knew what we needed and then you just don't get a chance to start on with the next season," Lewis said Friday in an interview with Boston's WHDH-TV.
He did not immediately return a message left Friday night by The Associated Press at his home in suburban Detroit.
Chiarelli said he has a short list of candidates to replace Lewis, but refused to comment on specific names. Chiarelli does believe it's critical for the team to have new leadership in place before the July 1 free agent signing period.
He said any free agent that's going to consider a place to play wants "to know who the coach is and what the coaching staff consists of," and said the replacement process will begin "right away."
The Bruins underwent a major housecleaning in the past off-season, bringing in Chiarelli and Lewis. The Original Six franchise hasn't won the Stanley Cup since 1972, missing the playoffs in each of the past two seasons.
The sudden removal of the two coaches is a major departure from comments Chiarelli made at the end of the season when he said, "I also know quick fixes don't work and so I have to be patient. I have to balance the two things because I know our ownership demands a winner and I know the city demands a winner."
It's that pressure from ownership and a fan base that has grown tired of watching a losing team that may have forced Chiarelli to pull the trigger on both Lewis and Habscheid.
He said both were surprised on Friday to learn they were being removed from their positions. "Anytime you're relieved of your duties, it's a hit on your pride. It was a tough day," said Chiarelli.
The general manager also said that he wouldn't "stand in their way" if Lewis and Habscheid get other job opportunities.
Lewis remains under contract with Boston for another three years.
Lewis said after the season that his history with the Red Wings may have blinded him to the work that needed to be done.
"I probably took a number of things for granted that I shouldn't, thinking that the players understand," he said then. "Where I came from, it's just sort of natural, which it really isn't natural. It's a learned process, so that's where I have to improve."