The Oilers (36-40-6) missed the Stanley Cup Playoffs by 17 points after reaching the Western Conference Second Round last season.
"After this season, they (the coaches) will be under close scrutinization," Chiarelli said. "I have to look real close at it and I have to dig deep, and I can't say with certainty, but on the surface, you would think, yes, I have to make some changes. I'll leave it at that. I want to make sure we look at every facet of the coaching staff."
McLellan's staff includes assistants Jim Johnson, Jay Woodcroft, Ian Herbers, and goaltending coach Dustin Schwartz. Edmonton was among the favorites to win the Stanley Cup at the start of the season.
"On a whole, it was a challenge for our coaches this year," Chiarelli said. "The challenges were created by expectations coming in. Challenges from how we were to manage in-game, how you were to manage that game to game. What happens is things start to go south a little bit and it's hard to pull them back, and that becomes a challenge for the coaches. It becomes a challenge for the [general] manager."
McLellan is 114-109-23 in three seasons with the Oilers. He signed a five-year contract in May 2015 to become Edmonton's seventh coach in eight seasons.
"The performance of the team is on my shoulders," the 50-year-old said Monday. "I'm the head coach, I accept responsibility for that. I have to look in the mirror first and evaluate what I'm seeing and whether or not I like what I did this season and what I need to adjust to. That will happen."
Chiarelli said he needs to evaluate the roster but does not intend to make massive changes to a lineup that is led by NHL scoring leader Connor McDavid. Defenseman Darnell Nurse is the only significant pending free agent (restricted).
"We're not going to dismantle this team," Chiarelli said. "We have areas where we have to fill and we have areas off ice that we have to look at. There are things we have to adjust immediately, but by no means are we going to dismantle this team. I expect this team to be in the playoffs next year and that's what we're striving for."
