A few weeks after Sergio Martinez got knocked down four times and eventually stopped in the 10th round by Miguel Cotto on June 7 in New York -- a defeat that cost him the middleweight championship -- Martinez vowed to fight on.

But whether the 39-year-old Martinez (51-3-2, 28 KOs) really does continue to box will depend largely on what his doctor has to say, particularly about his knee problems, following an exam due to take place Sept. 16 in New York, Martinez's adviser, Sampson Lewkowicz, told ESPN.com.

Lewkowicz will be with Martinez in Belfast, Northern Ireland on Sept. 6 when junior featherweight titlist Kiko Martinez, whom Lewkowicz promotes and Martinez (no relation) manages, defends his belt in a rematch with Carl Frampton.

Lewkowicz said that following the fight, he and Sergio Martinez will travel to Las Vegas to attend the Sept. 13 rematch between pound-for-pound king Floyd Mayweather Jr. and Marcos Maidana. They will be rooting for Maidana, Martinez’s countryman from Argentina.

“After the fight, we will go to New York together and Sergio will see his doctor,” Lewkowicz said of Dr. Answorth Allen, who is the orthopedic surgeon for the New York Knicks.. “He will have a complete checkup. We will listen to what the doctor has to say and then make a decision about his future."