Valencia feared for his season after picking up an injury at Ajax on Thursday.
He told The Sun: “After my last injury experiences I feared the worst.
“I was anguished but after tests the medical staff have confirmed a muscle rupture in the hamstring. It’s important but not grave – I should be back in a month.
“I am angry because it has happened at such a key moment in the season for United. I have developed and played some good matches and that’s the worst consequence of all this.
“But now the doctors have calmed me down and I have to recuperate and then help the team in our race to win the Premier League and Europa League.”
