The 21-year-old has made five Premier League appearances since joining in January, and Solskjaer hailed the young winger for his contribution against Everton and his continuing progress off the pitch.
"The boy is ready to play 90 minutes. It is just my decision," he said.
"Wilf came on for the last 20 minutes at Everton and I thought he did enough to win us the game, but we just never got the decision.
"He was fantastic when he came on. But it's about making sure we get the tactical set up for every game right."
Cardiff's battle with relegation has reduced Zaha's starting opportunities but Solskjaer says he's been impressed by his work ethic while in Wales.
"The boy has been outstanding when it comes to his attitude. He works very hard in training and I have never doubted his abilities.
"He's a good lad who just wants to play football. He's never been a problem, he just works hard and wants to be part of the team.
"It's just that we are in a situation now here when you have to make decisions."