The Red Devils head coach had to leave defender Lisandro Martinez out of his squad at the weekend.
"He's injured," Ten Hag told reporters post-game.
"Another one. So Licha had an issue, and he recovered from that. But, still, he needs some build-up.
"It's about the players who are available. We have to deal with the players who are available. So we don't make an issue from it. With the line-up we come with, we have to win."