Below the Belt by Jeanette Murray

Athletic trainer Marianne Cook is ready to do whatever it takes to turn the men of the Marine Corps boxing team into fighting machines. After all, her ultimate goal is to land a job training professional athletes. But when she notices a certain hard-bodied marine trying to hide an injury, Marianne realizes that she’ll have to use covert tactics to get him talking.
First Lieutenant Brad Costa has waited years for the chance to fight for a spot on the Marine Corps boxing team, knowing he has to push twice as hard to get half as far as his younger counterparts. Brad tries to downplay his injuries to the attractive trainer who has his dreams in her hands, but Marianne isn’t buying it. Maybe it’s time to deploy some targeted flattery.
As Brad and Marianne’s attraction turns red-hot, there’s more than one person having a hard time keeping their eyes on the prize…