The Plymouth Argyle boss says United have changed managers too many times over the past decade.
Rooney said: “Well that’s obviously down to the owners of the football club to look at that. I’m sure Erik Ten Hag is a fantastic manager.
“He’s won trophies wherever he’s been and won trophies at Manchester United as well. So yes, he’s going through a difficult period and I think he’d probably say that himself.
“But you hope he can turn it around because too often managers lose their jobs and then it’s another rebuild with a different manager.”
He added: “I think it’s difficult and anyone would admit that Manchester United want to be challenging for titles, so to be 14th, I’m sure everyone at the club knows they need to improve on that.
“I know Erik Ten Hag is doing everything he can to try and improve that. Players again, and I said this last season, need to do better than what they’re doing. There’s a big turnaround of players over the last few years. You just want to see them challenging again.”
Rooney also said: “It’s not for me to give Erik Ten Hag advice. He’s Manchester United manager and a very experienced manager as well.
“When you’re going through a tough period the important thing is you knuckle down, you work hard, you try and do the basics right. I think they showed good spirit to pick up a point against Villa, but the fans probably want to see a bit more and hopefully they can start doing that.”