Arshavin, now an adviser to Zenit St Petersburg, said: "Rooney is a strong footballer, with the physique of a rugby player.
"Such a guy is a collective farmer, a hard worker.
"In the game, he could do a lot, had a good control of the body even with such a physique, with his height he played well with his head. Excellent speed, great shot, physical readiness, was a real scorer. He was a great player, but anyone who played on the cutting edge at Manchester United scored a lot."
On Rooney's appointment at Derby, Arshavin continued: "Now the trend is like that, young coaches are in fashion.
"(Julian) Nagelsmann led the team in Germany at a young age. (Thomas) Tuchel, Pep (Guardiola) - they were not old either. They show good results, so others want to implement this in their club. But in football 10 teams cannot win at once, there is only one winner."