England prop Alex Corbisiero is to undergo further knee surgery next week after suffering another setback during an injury-plagued career.
Northampton rugby director Jim Mallinder revealed that the Saints loosehead will be operated on next Tuesday after watching his team edge out Aviva Premiership rivals Bath 13-11 at the Recreation Ground.
Corbisiero, a star of the 2013 British and Irish Lions' Test series win against Australia, has not played for Northampton so far this season.
He missed out on England's World Cup squad, and the 20 times-capped forward now faces more time sidelined after previously suffering a number of knee and shoulder issues.
Corbisiero, 27, has not started a Test for England since 2012, and Mallinder said: "He will unfortunately have to go in for another operation on Tuesday. He will be out for a few more weeks.
"It is just a bit of a clean-out, so it is not major. He has got a bit of a niggle going on in there.
"It is not good for him, but he is being positive and we are being positive about it. The surgeon is confident he can sort him out.
"I think the Six Nations is a very long way off for him. He will be thinking about recovering and getting back into the Saints' team, because at the moment he has two very good lads ahead of him."
Saints were also without Corbisiero's fellow England forwards Tom Wood, Courtney Lawes and Dylan Hartley against Bath, but Mallinder delivered a reasonably-positive fitness bulletin ahead of next weekend's European Champions Cup clash against Racing 92 in Paris.
"Lawes (knee) is hopefully back next week," Mallinder added. "He is back out running - we think he will be available next week.
"Hartley and Wood, I am not sure. Wood has got a shoulder injury and Hartley is recovering from his concussion."
Northampton maintained their recent dominance over Bath after fly-half JJ Hanrahan's late penalty shaded a dour contest.
Wing Semesa Rokoduguni looked to have condemned Northampton to a fourth Aviva Premiership defeat of the season after his classy second-half try put Bath in front, but Hanrahan had other ideas.
Rokoduguni's touchdown followed two George Ford penalties after Northampton led through centre Luther Burrell's try when he intercepted a Ford pass, while Hanrahan landed an earlier penalty and conversion.
Bath head coach Mike Ford, though, was left bemused by a plethora of scrums during the game. Asked how frustrated he felt, Ford said: "On a scale of one to 10? 10.
"I am frustrated by the scrums. It is just a lottery. We did what we did against Leinster two weeks ago, we went to Leicester last weekend and it was 50-50, and today it was the flip of a coin.
"We've got referees who are refereeing scrums, and they don't know what is going on. It is ruining the game. They are deciding who wins games.
"We are 13-11 down with seven or eight minutes left, and six or seven minutes of that eight minutes are scrums. It's not the game, we need the ball in play.
"We need to fix scrums. Is there anyone here can tell me what went on in the scrums today? We didn't get everything right, but the scrums are having too big an influence on the game.
"But, look, we are not playing good enough. We are better than that. The things we can control, we are not controlling as best we can. We will take our medicine.
"We will look to get back on the horse against Wasps in the Champions Cup next weekend."