West Ham forward Marko Arnautovic has vowed to "come back strong and quick" as he looks set to be "out for a while" with a suspected hamstring problem.
The Austria striker, who has scored five goals for the Irons this season, was forced off during the first half of Tuesday night's 3-1 Premier League win over Cardiff.
Arnautovic posted pictures of his leg in a straight knee sleeve and said on his Instagram story: "Lets Go I will do everything to be back for my team @westham
"Thank you so much for all your messages. I will be out for a while but will do everything to come back strong and quick".
West Ham have yet to confirm the full extent of Arnautovic's injury, but wished the forward a speedy recovery in a post on the club Twitter account, which said: "Get well soon, Arnie".
Irons boss Manuel Pellegrini is set to hold a pre-match press conference on Thursday ahead of the weekend fixture against Crystal Palace, when more is expected to be revealed on Arnautovic's expected lay-off.
Depending on the extent of the problem, Arnautovic could struggle to feature over the festive schedule.
West Ham have a home match against Watford on December 22, then are away at Southampton on December 27 before a trip to Burnley and hosting Brighton on January 2 with an FA Cup third-round date versus Birmingham set for three days later.
The Hammers recovered from the loss of Arnautovic to make it back-to-back Premier League wins for the first time in almost two years by beating Cardiff.
Two goals from substitute Lucas Perez – his first in the top flight for precisely 700 days – and Michail Antonio's first league goal of the campaign lifted West Ham towards mid-table.
The Irons prospects suddenly look a lot brighter than after the first four matches of the season, all of which were defeats to leave Pellegrini's men playing catch-up.
With fixtures against Palace, Fulham, Watford, Burnley and Southampton all to come in December, Antonio feels West Ham should be targeting a place in the top half by the turn of the year.
"We've scored six goals in the last two games now," said Antonio. "We didn't get any points from the first four games this season, so now we're clawing back those points we missed out on at the start.
"We need to take points from the teams around us in the next few games and see how high we can go in the league."
Cardiff, meanwhile, remain without an away win this season but would have taken a first-half lead had Joe Ralls converted a penalty.
Instead, they only managed a stoppage-time consolation through Josh Murphy.
Boss Neil Warnock is desperate for reinforcements in January with a midfielder and a striker his priorities.
"I'm hoping we can get three or four to help the lads that are here," he said.
"If I didn't get another defender, it wouldn't worry me.
"More importantly we've got to have someone up our sleeve if something happens to (Aron) Gunnarsson and we've got to have a striker as we can't ask (Callum) Paterson to do it, even though I thought that was his best game."
