West Ham will be without centre back Danny Gabbidon for up to four weeks due to a hamstring injury.
The Welsh international suffered the problem in The Hammers' 1-0 win over Sheffield United at the weekend as he was stretchered off after 63 minutes following a challenge from Christian Nade.
Gabbidon has been an ever-present for Hammers boss Pardew in The Premiership this season, and his absence for the Christmas period is a substantial blow for a team looking to claw their way back up the league table.
"Danny has suffered a grade two tear to his lateral hamstring muscle and the estimated recovery time before he is back playing again is around four weeks," confirmed head physiotherapist Steve Allen.
"We are hopeful that he may be back sooner than that but his recovery won't be rushed.
"We arranged the scan for yesterday so that he could begin his rehabilitation as soon as he arrived for training this morning and he is already responding well to treatment."
Gabbidon has forged a good understanding with Anton Ferdinand in the heart of the Hammers backline, and the 27-year-old was disappointed to hear he is likely to spend a month on the sidelines.
"Obviously it's a major disappointment for me," said Gabbidon.
"I hadn't felt my hamstring at all before the actual injury occurred, so it's just one of those unfortunate things that can happen in football.
"I am in good hands with the medical team at West Ham, though, and I hope to be back as soon as possible."
Gabbidon's absence could open the door for international colleague James Collins who has just returned to training at Upton Park after recovering from a groin problem.