The betting line is now available for Israel Adesanya vs. Anderson Silva, and the former UFC middleweight champion is a sizable underdog.

Silva (34-8 MMA, 17-4 UFC), 43, will return from a two-year hiatus at UFC 234 in February when he meets undefeated Adesanya (15-0 MMA, 4-0 UFC) in a matchup that will apparently determine the next title challenger at 185 pounds.

5Dimes (via BestFightOdds.com) has released opening odds for the bout, and Adesanya stands as a -400 favorite against the +280 for Silva. That means a $100 bet on Silva would net $280 in return, while $400 would need to be placed on Adesanya in order to gain $100.

UFC 234 takes place Feb. 9 at Rod Laver Arena in Melbourne, Australia. Adesanya vs. Silva co-headlines the pay-per-view main card.

For more on UFC 234, check out the UFC Rumors section of the site.

Gallery Photos: Best of Anderson Silva view 119 images