Newcastle winger Sylvain Marveaux faces up to four months out after undergoing surgery on his right hip and groin.
Marveaux flew to the United States for the operation at the Steadman clinic, having limped out of the 2-1 win against Everton earlier in the month.
"Sylvain has been to America and the op was a success," Newcastle manager Alan Pardew told the Evening Chronicle.
First-team opportunities have been limited to three starts in all competitions so far this season.
Meanwhile Danny Simpson's future at the club is yet to be confirmed, with the defender still to agree on an extension to his contract that expires in the summer of 2013.
The 24-year-old joined Newcastle on a permanent basis from Manchester United in January 2010, and has made 65 appearances.
"Danny is a player who has broken into a Premier League team here at Newcastle, which is a big club, and he has done very well," Pardew added.
"We want him to secure his future here.
"Contract negotiations are ongoing, but my personal preference is for him to sign quickly because he has got a lot of competition in that area."