The two Norwegians face off tonight in the Europa League quarterfinals in Germany.
Solskjaer said, "We are not the ones to play against each other. But I have known him for many years. He had a very good career as a player, and he is in the process of creating a legacy in Copenhagen that is now in the quarterfinals for the first time.
"He's a little older than me. You probably see that. I'm starting to get grey in my hair, but I hope I at least keep my hair!"
The United manager added: "I know how Stale has built up the club. I played a lot against them with Molde, and I have known Stale for so long. Copenhagen has a history of doing well in Europe. Their greatest strength is the collective and the way the team is organised."