The Arsenal star is set to star for Germany in France this summer.
The playmaker enjoyed a strong season for Arsenal, topping the assist charts with 19 in total across the campaign.
That tally saw him fall just short of the record of 20 set by Gunners legend Thierry Henry, but it was far superior to the rest of the competition in the top flight.
His attention now turns to Euro 2016, where he will star for reigning world champions Germany.
And Hamann has backed Ozil to be a key player as Joachim Loew’s side look to add the tournament to their World Cup success.
“He’s maybe a bit underrated for the German side, even though he has always had a big role to play,” he told the Daily Star.
“I think perhaps he’s also a bit undervalued in Germany, but he will be one of the key players at Euro 2016 because he can make things happen that nobody else can.”
It will certainly be interesting to see if Ozil can perform at his highest level at Euro 2016, with the pressure firmly on Germany.
He has often been accused of lacking consistency, but dispelled that this past season as he was the star for Arsenal over several months.
Ultimately the Gunners ended the season disappointingly, and he will be hoping this tournament does not end in a similar manner.