(Reuters) - Struggling West Ham United are unsure when striker Andy Carroll will return to action as he continues to recover from what manager Slaven Bilic described as a "very strange injury".
The 27-year-old has been sidelined since injuring a knee against Romanian club Astra Giurgiu in the Europa League in August and has played only one Premier League game this season.
"It was a very strange injury," Bilic told a news conference on Thursday. "Originally it was four to six weeks (on the sidelines), and we were fuming about it.
"It was a shocking prognosis, but now it's way longer than that so all that I can say is he's working really hard, he's progressing, but its slower than we expected.
"All I know is that it's about weeks -- but then it was about weeks at the beginning when it happened."
West Ham's record signing Andre Ayew is back in training but Bilic said it was unlikely the Ghana international would make the squad for Saturday's visit of bottom-side Sunderland, who are the only team in the league not to have won a game yet.
West Ham are 15th in the table and a point above the relegation zone after two wins and five defeats, and Bilic said opponents would look to take advantage of his team's struggles at their new home.
The Hammers swapped Upton Park for the London Stadium at the start of the season, but have won just once at home, with matches marred by a series of below-par performances and infighting among fans.
They snapped a five-game winless streak with a 1-0 victory at Crystal Palace last weekend, but Bilic is aware they need to improve further if they are to put more daylight between themselves and the drop zone.
"We have one win from four home games in the league. Opponents are hoping to capitalise on that in a new stadium. It is our home and we need to change that," he added.
"You can talk and analyse, but the best thing to get the confidence back is to win a game and we kept a clean sheet as well. You can move away from the bottom with a few wins."