The Hearts striker was booked inside the opening 60 seconds at BT Murrayfield as Brendan Rodgers’ side advanced to the Betfred Cup final after a convincing win over the Capital club.
But midway through the first half, MacLean and Kouassi clashed at a corner, with the Ivorian midfielder hitting the deck and looking to be in some pain.
TV pictures showed the pair tussling in the six yard box before MacLean, who had his back to his opponent, appeared to grab the 20-year-old’s privates.
After the match, MacLean brushed off his tussle with Kouassi, saying: “It was just a laugh, just a coming together. If I went down every time a centre-half niggled me I would be on my backside all day. It was just handbags.”
The 36-year-old striker was on a yellow card at the time of the incident and referee Willie Collum spoke to the pair afterwards, but didn’t take action.
Kouassi was replaced by goalscorer Scott Sinclair after 26 minutes.
The midfielder had been hobbling after landing awkwardly earlier in the half but it was unclear if it was that or the incident with MacLean that had rendered him unable to continue.
Celtic won the match 3-0 and will face Aberdeen in December’s final.