Irwin has watched Kagawa in action for Borussia Dortmund and believes it wonâ€™t take long for the Japanese midfielder to become a crowd favourite at Old Trafford.
Irwin told ManUtd.com: "Heâ€™s the type of player that most United fans felt we needed, an attacking, all-action player.
"I saw him playing a couple of matches for Borussia Dortmund and he seemed a very talented player, lively with great technique. I know he was highly rated in Germany.
"I think heâ€™ll be a great signing and fans should be excited by the prospect of him playing for us because he can run with the ball, create chances and score goals. Heâ€™s just what we need."