Oh boxing, what would we do without you? For Thanksgiving, Manny Pacquiao was thankful for Twitter. On what other platform can you tweet "Happy Thanksgiving" at a fighter from another sport and generate some free buzz? Pacquiao did that just that, tweeting a picture of Conor McGregor telling him to "stay fit" before adding the hashtag "#realboxingmatch."

After seeing the draw that Floyd Mayweather had against McGregor, it's an interesting proposition. We aren't far removed from a time that Mayweather-Pacquiao was the biggest fight ever. It wasn't a threatening challenge on Pacquiao's part, more of an invitation in the tweet.

Pacquiao's last fight was in July, where he lost to Jeff Horn in front of Horn's home crowd in Brisbane, Australia to drop the welterweight title in extremely controversial fashion. Pacquiao and Oscar De La Hoya have challenged McGregor in the past month, but McGregor has been noncommittal about returning to that particular ring.

McGregor has also had other things to worry about. He was allegedly pulled from Dec. 30's UFC 219 after inciting a brawl at Bellator 187 in Ireland. Although it's unknown if he'll get back into the ring, Pacquiao is the perfect person to issue this challenge -- Pacquiao may not be what he was in 2015, but he's still a big boxing name. He's part of one of the biggest cards of all time. And McGregor takes those kinds of challenges to heart.