McCall said the player had been “overwhelmed” by the support he had received from the rugby community.
“You saw the reaction of some of our players who were close to the incident, I can’t remember people reacting like that too often,” McCall said.
“I thought the crowd at Quins were brilliant in giving him an ovation off the field, I think everyone realised how serious it was.
“I think Andy has been overwhelmed by all the support he’s got from a lot of places. He’s been buoyed by that.”
Onyeama-Christie joined Saracens in 2018 and has made 85 appearances for the club, winning two Premiership titles, the Championship and the European Champions Cup in that time.
He made his Scotland debut against France at Murrayfield in the Six Nations in 2022 and has eight caps for his country.
Onyeama-Christie missed the end of the domestic season last year with a broken arm that also ruled him out of Scotland’s summer internationals.
He had missed the end of the previous season with a broken forearm.
“He’s one of those characters who, once he gets his head around it and once the surgery’s done, he’ll be very determined to come back as quickly as possible, like he’d done with his broken arm, better than ever,” McCall added.
