"Gareth Barry will undergo minor surgery on his knee injury next week... (and) is likely to be ruled out for the remainder of the Premier League season," West Brom said in a statement on their website.
The injury layoff is a further setback for Barry, who was one of four West Brom players interviewed by Spanish police over the alleged theft of a taxi during a training camp in Spain in February.
Relegation-threatened West Brom are bottom of the league with 20 points from 32 games and take on fellow strugglers Swansea City on Saturday.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Toby Davis)
