A training injury has forced lightweight prospect Erik Koch from his UFC 203 bout against Drew Dober. Stepping in for "New Breed" on September 10 in Cleveland will be Octagon newcomer Jason Gonzalez.

In the main event of UFC 203, which takes place at Quicken Loans Arena, hometown hero Stipe Miocic defends his UFC heavyweight title for the first time against Alistair Overeem.

California's Gonzalez, winner of six straight, has finished all ten of his pro victories, with six wins coming by submission and four by knockout. Approaching his three-year anniversary in the UFC, Dober is coming off a win over Scott Holtzman in January.