Aaron Simpson to fight July 11

Aaron Simpson will make his welterweight debut July 11 against Kenny Robertson, UFC announced Tuesday night on Fuel TV.

The opportunity for Simpson to fight arose when Jon Fitch was deemed unable to compete due to a knee injury. The Simpson-Robertson fight will take place at UFC on Fuel TV 4 in San Jose, Calif.

Simpson (11-3) opted to leave the middleweight division following a Feb. 15 split-decision loss to Ronny Markes.

"I've had some success with these bigger guys," Simpson said May 14, when he announced his decision to drop to 170 pounds. "I weigh about 193 pounds right now as we speak and I've yet to cut down.

"In my last fight against Ronny Markes, he tweeted that he weighed 218 pounds and I weighed 191 pounds in the fight. In all my fights, I've been the smaller guy. It will be an advantage for me to at least be the same size as my opponent, if not a little bigger."

Robertson (11-1) returns to UFC for the first time since making his lone appearance in the promotion on Feb. 5, 2011, when Mike Pierce stopped him by TKO in the second round.