The 19-year-old left the Showgrounds on crutches before heading to hospital for an X-ray which revealed a fracture to the foot as well as ligament damage.
“It’s a bad blow for Michael and for us,” said Ballymena boss Glenn Ferguson.
“Saturday was his first start after forcing his way back into the starting line-up so it’s very disappointing and we will focus on making sure he makes a full recovery.”
The injury is blow which Ferguson could ill afford, given that his playing resources are already severely stretched.
Key players such as defender Johnny Taylor and skipper Allan Jenkins remain sidelined, while Ferguson has a number of other unavailabilities to contend with as he prepares his squad for the visit of league leaders Cliftonville this Saturday (3pm).
“We’ll have a head count this week to see who’s available but we will have to wrap them in cotton wool because we’re down to about our last 16.
“We also have Gavin Taggart and Mark Surgenor suspended for this week’s game, so we really are down to our bare bones.
“The league table says that Cliftonville are the top side at the minute so we have to go out and do it all over again.
“They have been going superbly and they will offer a different type of challenge because they will play more football on the ground than Crusaders, whose style is more direct.
“That’s not something to fear because when they lose the ball, we will try to do something with it.
“It should be a game between two teams who like to pass the ball.
“It will also be a big test because when you switch off against top teams for 20 or 25 minutes you get punished the way we were against Linfield,” added Ferguson.
The manager has received a boost with captain Jenkins able to do some light training before Saturday’s match, while the skipper has also been working intensively on a cycling machine at home.
“Gordon McCartney is pleased with Allan’s progress and he is probably slightly ahead of schedule at the minute so we have his return to look forward to around the new year,” added Ferguson.