West Ham United boss Slaven Bilic has revealed that injured new signing Andre Ayew could spend less than three months in the treatment room.

The Ghanaian was withdrawn 35 minutes into his maiden appearance for the Hammers in a 2-1 defeat to Chelsea on Monday after hurting his thigh.

Initial medical examination and media reports had speculated a four-month recovery period.

“Andre is very optimistic and he is good," Bilic told pressmen on Friday ahead of Sunday's league clash with Bournemouth.

"He is professional and has approached even this injury, having spoken to many people, with optimism.

"He could be out for two-and-a-half months, or four months, but he shouldn’t be out for longer than four months.

"He could be back this year and we just have to hope without moaning or crying."

Bilic also shed light on the possible treatment options available for the 26-year-old's rehabilitation.

“It’s not the first time when an injury of this scale has two opinions and solutions," Bilic said, "one is surgery and one is without.

"We are going to speak to the medical staff and see what we think.

"I am not a doctor, so I will listen to them! It doesn’t have to be today that we decide.

"He’s going to be out for not long long, but a longer time! We have time to make a proper decision."

Ayew completed a three-year move worth £20.5 million from Swansea earlier this month, a season after joining the Welsh side from French Ligue 1 outfit Marseille.

He netted 12 times in 34 Premier League appearances for the Jack Army.