The Nice frontman only arrived in Scotland on Friday after agreeing a one-year loan but was thrown straight into the Saints side just 24 hours later for the 2-1 defeat to Partick Thistle in Paisley.
The 21-year-old was not given the chance to train with his new team-mates but looked good early on as he muscled his way into a scoring position only to see Conrad Balatoni hack his effort off the line.
However, from there his display looked ever more erratic and Bahoken - a former team-mate of Esmael Goncalves, the Portuguese striker who arrived a St Mirren Park on loan last season and helped the club to their League Cup triumph - was hooked at the break.
But McLean hopes the Frenchman can still come good.
"It was frustrating for Stephane," McLean admitted. "It was always going to be tough for him to come straight into the team.
"But look at Isma last year. Sometimes it works, sometimes it doesn't. Hopefully he can still be a big player for us in the season to come."
McLean put Saints ahead when he volleyed home from David van Zanten's low cross five minutes after the break but the hosts failed to build on their lead.
That allowed Callum Higginbotham to curl a beautiful finish past on-loan Swansea keeper David Cornell before Ross Forbes fired the winner for the Jags with six minutes left, leaving Saints boss Danny Lennon to face another furious response from the Paisley public.
St Mirren are yet to win a game this season and have triumphed just once since their Hampden Park victory over Hearts six months ago.
McLean said: "That's three defeats in a week which isn't the best obviously. We need to learn to see games out and to keep clean sheets.
"We know we've only won once since the cup final but if we could put our finger on why that has happened, we'd stop it but it's a hard run we've been on since the start of the season.
"The only point we have picked up is Killie at home. We need to change that quickly. We can understand the fans' frustrations, of course we do. They pay good money to come here and if we are not winning, they are going to get on our backs.
"That's our jobs we need to take that. We need to stick together and they could just get behind us hopefully we can pay them back soon."
Thistle match-winner Forbes added: "It was a deserved win and we dominated. They defended quite well but we had chances we didn't take.
"The boys believe we deserve to be here and we always had faith the goal would come.
"Our main aim is survival and we want points on the board early to give ourselves the best chance. We didn't let our heads go down at 1-0."
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- Partick Thistle
- Conrad Balatoni