Nyoni laid on Dominik Szoboszlai's winner in Pittsburgh.
Slot said afterwards: "I think he did really well today but it was only an hour. Like I said, he did well. He was one of the reasons why we scored the goal, because he turned really quickly and a spot-on pass in between the lines. And he was also involved in the biggest chance in the second half. So he did well.
"But he's just turned 17 and his body has to grow, and we are really careful with him. So he doesn't join every session and sometimes he goes out a bit earlier because he only turned 17 and you can see his quality but you can also see his body still needs some time to grow to play at Premier League level. But he showed some interesting things today."
On fit-again Bajcetic, Slot also stated: "I think you have to take into account with Stefan that he was out for a year, one-and-a-half years almost. So if a young player is out for that long, you have to give him some time. But I saw today already a few good moments from him and also a few moments where he got caught because he acted a bit too slow.
"But I think that's normal if you've been out for such a long time, then you need rhythm, you need game time to grow even further. But I think he showed some good moments during the half-hour that he played."