But he backed the 23-year-old to "come again" after Curtis Main replaced his fellow Englishman for Tuesday's 3-1 win over Hamilton Academical.

Aberdeen had failed to score in five outings since Cosgrove's 21st goal of the season, against Dumbarton.

"There comes a point where others deserve an opportunity," McInnes said.

"Sam has carried a burden for a while. When you've got a 21-goal striker in the building, any manager would be reluctant to leave him out.

"It comes to a point where you have to be fair to the boy himself - and he will come again, whether he starts on Sunday or comes off the bench."

Cosgrove has contributed 44% of Aberdeen goals this season as the side sitting third in the Scottish Premiership prepare to entertain leaders Celtic.

"For the benefit of Sam, we might need him to come out of the team to get going again - we've seen that before with younger ones," McInnes said.

"For far too long, we've depended on him this season, looking for others to chip in - and the boy is deserving of a break. But he's too important for us to be a bit-part player."

Main scored one of Aberdeen's three goals against Hamilton and McInnes praised the 27-year-old's performance while admitting that too many players in other positions have not justified selection this season.

"Curtis led the line well - he was part of a very good team performance," he said. "It was great to see him get the goal, run the channels, which we want to see more of."

McInnes hopes it is "a sign of things to come" not only for Main but for the team as an attacking threat.

"Too often this season in other areas - wider areas in particular - players have not done enough to say after the game 'that's me sorted for next week'," he said. "Players pick the team for the manager with their performances - and I think Curtis did very well the other night."

Main hopes to keep his place

Main himself does not rule out forming a partnership with his fellow striker but is leaving that decision to his manager as they look to conjure a "surprise" against visitors who have won 17 of their last 18 games.

"I was glad to get the opportunity and happy with the performance that I put in the other night, so hopefully I can stay in the team and do something similar," Main said.

"Whatever team is selected, we will all be raring to go. It's down to the manager to pick a team that gets a positive result."