3 West Ham boss Manuel Pellegrini speaks with Andriy Yarmolenko as he leaves the field on a stretcher against Tottenham Pushed on a time frame for Yarmolenko’s expected return, Pellegrini said at his press conference ahead of Saturday’s clash at Leicester: “It’s so difficult to know how he will recover, but I don’t think it will be less than five or six months.“You need to recover your best shape, recover your trust, it is not easy.”West Ham travel to Leicester looking to avoid a third successive Premier League defeat after a second halted their revival.Pellegrini added: “If you review our fixtures then in the first ten games we played eight teams in the top half, now we have teams that are similar to us. (However) that doesn’t guarantee you are going to beat them. The Ukraine international has had an operation to correct the problem and is now facing a lengthy spell of rehab.And while five to six months may be the official time frame, Pellegrini concedes getting the 29-year-old back firing on all cylinders and ready to make an impact by the start of May might be a tall order.The timing of the injury was cruel on Yarmolenko, who had begun to show signs he was settling into the Premier League, having scored two goals since joining the Hammers.And Pellegrini says losing him so early in the season is a ‘very difficult’ blow for the team.“Yarmolenko has had surgery and he will be out for around five months,” said the boss.“It’s very disappointing. He’s an important player for us. He’s one of the players who arrived this season, so we could have more technical players.“We also have Manuel Lanzini and Jack Wilshere out, so three players in the same position are out.“It’s a real pity and it’s really difficult for the team.” 3 Yarmolenko appeared in serious pain when he came off at the London Stadium Pellegrini knows he has to spark an upturn in fortunes, having only won twice so far this season 3 Manuel Pellegrini has said West Ham forward Andriy Yarmolenko may struggle to play again this season after undergoing surgery on his Achilles injury.The summer signing, who arrived from Borrusia Dortmund for around £18million, is set for five to six months on the sidelines after he was stretchered out of Saturday’s 1-0 defeat to Tottenham. “Our best games we played were against Arsenal, Manchester United and Tottenham, Chelsea, the big teams.“We must know where we need to improve and play like we did against Tottenham for 90 minutes, but we need to start scoring.”Midfielder Pedro Obiang is carrying a calf problem, so will not be available for Saturday’s clash, while Carlos Sanchez and Winston Reid remain sidelined.Leicester City manager Claude Puel, meanwhile, said Jamie Vardy is a doubt for the game.