Real Madrid go up against Juventus in Cardiff aiming to become the first team to retain the Champions League in its modern format.
At the spearhead of their side will be a resurgent Ronaldo, who goes into the contest after scoring 14 goals in his last nine games.
Ozil and Ronaldo were team-mates for three years at Real, where they won La Liga and the Cola del Rey together.
And the Germany international has lauded the former Manchester United star, saying his determination and drive is what has made him one of the best players of all time.
Top goalscoring teams in Champions League history – plus Cristiano Ronaldo Wed, May 3, 2017
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Mesut Ozil and Cristiano Ronaldo were team-mates at Real Madrid
"His ambition, how hungry for success he is, as a player, you're always quite similar," Ozil told Arsenal Player.
"You want to be successful, you want to bring your best and what fascinated me about him was how professional he was. He'd be the first in the dressing room and the last to leave.
"He's a grounded guy who is very ambitious, who always gives his best for himself and for the team. What I admired about him was how hungry for success he is.
Cristiano Ronaldo is aiming to win the Champions League again
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"He's not somebody who when he achieves something, thinks 'OK I can stop now, or I can go easy'. It's the opposite. He always wants to be more successful – he wants to defend titles and I admired that."
Ronaldo will be aiming to win a fourth Champions League title of his career this evening.
The 32-year-old first won the prize in 2008 with United, and has won it twice in the past three seasons.