Ball out of action for 10 weeks
The 24-year-old second row powerhouse damaged his left knee during the 27-26 Boxing Day derby defeat against the Ospreys and has been told he will be out of action for 10 weeks. That means he will not only miss rounds five and six in the Champions Cup, but also the Six Nations games against Ireland, Scotland and France in February.
He is expected to be back around the beginning of March so could come into contention for Wales' away trip to Twickenham Stadium on 12 March and the final game of the championship against Italy at the Millennium Stadium on 19 March.
"Jake got hit with a chop tackle and he's got a tear in his ligament. He's going to see a specialist, but he is going to be out for at least a couple of months," said Scarlets head coach Wayne Pivac.
"We are hoping it is just going to be a rehab job, but we won't know the full story until he has seen the specialist."
Better news for the Scarlets is that Wales fullback Liam Williams is due to start running next week after recovering from a second operation on the foot the damaged once again in the World Cup defeat at Twickenham against Australia.
"It will be great to see Liam back up and running next week. "We are doing everything we can to get him right for both the Scarlets and Wales, but we won't rush him back and won't put any pressure on him," added Pivac.
The Scarlets have to travel to Pool Three leaders Racing 92 in round five and then host Northampton Saints in Round Six. They have yet to win a game in Europe this season.
