It not only crushed his chances of a PRO12 debut but also involvement with Scotland at the World Rugby U20 Championship last month.
But Alan Solomons could well call on Kerr at some point next season with World Cup-bound hooker Ross Ford facing a heavy schedule - and the teenager insists he can see light at the end of the tunnel.
"During one of the training weeks for the Six Nations I suffered a knee injury, it was a bit of a shock and I was gutted at the time," Kerr told the Edinburgh Evening News.
"I had fully ruptured my PCL [posterior cruciate ligament] and suffered a grade two tear of my MCL [medial collateral ligament] and to know that I was going to miss the rest of the Six Nations and then the World Championships in Italy was pretty tough.
"At first I got too bogged down in thinking how long my recovery was going to take, but I know things need to be right and I have been working hard with the physios to get back to full fitness.
"There is still a bit of a way to go, but I am determined to keep focusing and come back stronger.
"I have a scan in a couple of weeks to see how much muscle I have got back in my leg."
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