Hook had hoped to go head-to-head with the Irish points machine in tonight's Magners League top-of-the-table clash between his Ospreys side and Munster.
But a hamstring injury suffered against Ulster last weekend has ruled out O'Gara for a fortnight.
Nevertheless, Hook is full of praise for the 2001 and 2005 Lion and believes he is on course to make it a hat-trick of tours.
"Ronan is a complete player and the best fly-half in Europe on form at the moment," said Hook, who is preparing to show off his credentials to Ian McGeechan when Wales defend their Six Nations title.
"There are a few fly-halves fighting for that top spot like Danny Cipriani, who is a quality player but struggling for form, and Jonny Wilkinson, who is injured.
"But Ronan is a tremendous player with great experience. He has a fantastic tactical kicking game and his goal-kicking is brilliant."
The 23-year-old Hook is already battling with Scarlets rival Stephen Jones for the Wales No 10 shirt and he is now setting his sights on toppling O'Gara as well as the race for the Lions outside half role to face the Springboks moves sharply into focus.
"I don't fear Ronan, but I respect him because he is one of the best. I want to enjoy playing against him and I'm really get excited at the prospect," admitted Hook.
"The coaches have said I need to improve my game management. When you are a No 10 it's really difficult to control a whole game, but Ronan is someone who can do that.
"I'm still learning and trying to reach that level. The more I play, the more I will improve."