Marosi cut his hand and dislocated a finger making a save early in the second half of Saturday’s 2-1 win.
But he stayed on after lengthy treatment and preserved the victory for his team with a brilliant stop to deny Brewers substitute Sam Winnall.
“I thought he was magnificent,” said Cotterill. “I think he has probably earned himself a few days off because I can’t see him doing much goalkeeping.
“He is OK and will be alright for next week. But he is going to be sore for a little while.”
Marosi’s injury led to 13 minutes of added time but Town hung on to claim their second home win of the campaign, which saw them climb to second in the League One table.
Christian Saydee opened the scoring in the 13th minute against his former club but Burton more than deserved the equaliser netted by Victor Adeboyejo just prior to the hour mark.
A tactical tweak helped Town stem the flow and Ryan Bowman scored the winner just four minutes after coming off the bench.
“It was an eventful game,” said Cotterill. “I think I overtrained the players this week. I think that is why there was a bit of lethargy in us from 60 minutes on. There is a lesson in there for me.
“But when you are on the back of a defeat, you want to put it right. I thought the subs that went on had an impact. Today was one of those lucky days.”