Joshua stopped Michael Sprott inside the first round in November and Betway make the unbeaten English heavyweight evens to repeat the feat.
The London 2012 Olympic gold medal winning champion is 1/200 to win at any time in his first fight since pulling out of a bout with Kevin Johnson in January with back trouble.
Joshua has yet to be taken past three rounds as a professional.
Betway’s Alan Alger said: “Anthony Joshua is as impressive a heavyweight as we’ve seen in a long time, and he’ll want to show that he’s fully recovered from a back injury by dispatching Gavern in short order on Saturday.”
Anthony Joshua v Jason Gavern Specials
Anthony Joshua 1/200
Jason Gavern 25/1
Anthony Joshua to win
Inside 60 seconds 6/1
Inside 120 seconds 5/1
Inside 180 seconds 4/1
In the 1st round 1/1
In the 2nd round 2/1
In the 3rd round 5/1
4th round or more 2/1