Slot was speaking ahead of Saturday's FA Cup third round tie with Accrington Stanley.
He said, "He's a talented player. He's been with us for so long. In recent weeks, he comes in quite a lot and gets his minutes, but like it is for him and many others, he's in competition with the other good players.
"He was very unlucky, I think after two games, he got injured, was out for a long time and what I've seen now with almost all of our players that have been out for quite a while that in this league - with the tempo, intensity and the quality we have, the other teams as well - it is not so easy to come back and be at your best immediately.
"That is the balance we have to find, to give them playing time to get to their best level, but still be able to win every game."
On his approach to Cup competitions, Slot said: "When I was at Feyenoord I said I was always unlucky with the draws, we had the most difficult one that we could get in that draw and that means you play the same team in the same league.
"So I don't remember playing against a lower league club in my managerial career, but I was only a manager there for three or four years."