Tennis star Novak Djokovic lost in the second round of the Cincinnati Open over the weekend and appeared to struggle with stamina throughout the match. On Saturday, he attributed his on-court issues to a health condition that has been bothering him "for the past couple of years" and said it's exacerbated by hot and humid conditions.

Novak Djokovic has responded to retirement rumors following his defeat to Thiago Agustín Tirante at the Cincinnati Open.

"I certainly hope so, but unfortunately, at this point it seems more likely that I won't. However, we'll see what the future holds."