(CNN) - Conor McGregor, the retired two-time mixed martial arts champion, has hinted at a return to the sport through a cryptic social media post on Monday. The short message, which reads: "Dublin, December 14th," was posted on his official Twitter account, raising speculation that he intends to return to the octagon in his home town later this year. The 31-year-old last fought in October 2018, when he was beaten by Russian mixed martial artist Khabib Nurmagomedov. Rumors have been swirling about a possible comeback since McGregor told ESPN in August that he "would look for" a fight for the "end of the year." McGregor has had a turbulent time away from the sport, hitting the headlines for allegedly punching a man in the head in April.