The 35-year-old midfielder is still club captain, but he has consistently been seeing less than 90 minutes in games under Lennon this term.
With Celtic chasing the game against Hibernian on Saturday, Brown was brought off in the 72nd minute and McManus admitted that it just does not look good if the club skipper fails to complete 90 minutes consistently.
He believes Celtic must look at the other side of Glasgow and how James Tavernier is the main man for Rangers, playing 90 minutes of football in almost every game for Steven Gerrard.
McManus stressed that the club captain not playing the 90 minutes sends the wrong signal to the rest of the squad and believes Lennon must either take the captaincy off him or leave him out on the pitch.
The former Scottish Premiership star said on PLZ Soccer: “I don’t think it’s a good look, subbing your captain off after an hour every week, I really don’t.
“Your captain should be your main man, he should be playing 90 minutes every week.
“I look over the other side of Glasgow, their right-back is the main man and the captain.
“I think if you are going to do that with Scott Brown, you either don’t play him or give someone else the captaincy.
“I don’t think you can’t keeping hooking your captain off after an hour, it just not a good look and just don’t send the right signal or the right message to the whole team.
“That is something Neil Lennon needs to look at. If you play Scott Brown, then play him for 90 minutes.”
“If he is not going to play him then he sits on the bench.”
Brown has completed 90 minutes seven times in the Scottish Premiership this season for Celtic.
