The 32-year-old sustained his AC Joint injury, which is similar to that of club mate Iain Balshaw, during the Zurich Premiership match against Bristol Shoguns in November and both players will undergo surgery on Saturday at the same location.
Despite making a brief comeback as a second-half replacement against French side Montauban three weeks ago, Lyle felt that his shoulder was not 100 percent right in the contact situation, and a decision had to be made as to the best way forward for the back row player.
"After seeing a shoulder specialist, it has been decided that Dan will need surgery. It is likely that he will be out for the next 12 weeks," said Bath co-coach Mike Foley.
Frontpage Image courtesy of the official Bath website