The 25-year-old joined the Club in September on a three-year deal and has impressed on tour in Australia before Christmas and in the Caribbean in February and March.
But in the Lions’ final unofficial One-Day International against the West Indies, the former Durham man was forced off the field after diving for the ball and landing awkwardly.
Coughlin will definitely miss the start of the season and no firm return date has been set for his comeback.
“He has been assessed and is going to have an operation on Wednesday,” said Head Coach Peter Moores.
“It’s obviously a very serious injury and we are not going to see him for a while, but in physio James Pipe and all the medical staff he’s in the best hands, and hopefully the surgery goes well.
“He’s got a fairly long journey back to fitness and we all feel for him because he’d just joined a new club and made a really good impression in terms of his ability and how he’s been around the other lads.
“He’s gone full length to try to get to a ball and with sport there’s always a chance of an injury. The commitment he showed in going for that ball is the way he plays his cricket – and why we were so excited to get him.
“I’m sure he will commit everything to the rehab which he will have to do, and realistically there is going to be a big chunk of the season which he is going to have to miss.
“We all feel for him and support him all the way through so that when he is ready to come back, he comes back with a bang because we know we are going to get a very good player.”