Wigan Athletic have confirmed defender Ivan Ramis will miss the remainder of the season after rupturing his cruciate ligament in Saturday's 1-1 draw at Fulham.
Latics boss Roberto Martinez feared the worst immediately after the game and scans have now revealed the Spaniard will be out until the start of next term.
"Nothing can disguise the fact this is a massive blow because Ivan is a key member of the group but we are relieved that the injury is not a severe as we feared it could have been," Martinez told www.wiganlatics.co.uk.
The news is a massive blow to Martinez as another senior defender, Antolin Alcaraz, is still to return after suffering a groin injury in August.
Wigan do have another alternative in Roman Golobart, but the 20-year-old's relative lack of experience means Martinez may be forced to use Emmerson Boyce as an orthodox defender, rather than in the wing-back role where he has excelled over the past 12 months.
A summer arrival from Real Mallorca, 28-year-old Ramis endured a difficult debut against Chelsea but has since come into his own, making 19 appearances.
He had only just returned from a hamstring problem when he suffered the latest setback at the weekend.
"The most important thing now is to think of Ivan's welfare, get the operation completed, and for him to begin his rehabilitation," said Martinez.
"Ivan is a very strong and positive character and he is determined to return to fitness as soon as he can.
"He will receive the best possible medical rehabilitation as the club ensures to have him return as an even stronger footballer."