It was only the Wales international's second Premier League start as he helped Arsenal to a 4-1 win against Wolves.
Wenger said: "He's 18 years old and people forget. I set him a target to play between 15 and 20 games this year. So at some stage when you set a boy a target you give him a chance. When we play every three days, I rotated it a little bit because I believe we have a real squad of 20 field players who are of a fantastic level and you can talk and talk and talk, but you have to do it on the pitch as well and give them a chance.
"He has improved a lot. He has a tremendous engine and he already has good experience for an 18-year-old player."