The club said on Friday Valencia had suffered what “appears to be a significant injury to his right knee and right ankle” and refused to put a time-frame on his return ahead of a meeting with a consultant.

But Valencia, who joined the club from Pachuca last summer, took to Instagram to post a picture of himself from the Astra game and wrote that he does not need surgery.

“I would like to thank everyone for the support and the affection shown on this difficult moment. Thanks God, today I received great news as I won’t need surgery, all the best!” he wrote.

With club-record signing Andy Carroll also out injured, Irons boss Slaven Bilic is still likely to add another striker to his squad before the transfer window closes.

He has Diafra Sakho, Mauro Zarate and Mobido Maiga to chose from for the return leg in Romania and their Barclays Premier League opener at Arsenal on Sunday, and the former Croatia boss admitted after Thursday’s draw that he was worried about the injury to his Ecuador international.

”I am worried, to be fair,” Bilic said.

”And this is the reason I am unhappy tonight. I am not happy with the result, of course, but this is not as important as the injury. It looks serious but we won’t know for sure until he has a scan.“

Despite announcing no surgery is needed, it remains unclear when Valencia will be available and a loan move for Atletico Madrid and Mexico forward Raul Jimenez has been widely reported, but the 24-year-old would require a work permit before making the move to Upton Park.