Thomas, 33, spent his entire 11-year career with the Browns before announcing that he is stepping away on Wednesday. He was in attendance for the Cavaliers' 124-117 win against the Milwaukee Bucks in Cleveland.
Fans gave Thomas a standing ovation during the game. James walked over to the future Hall of Famer and wrapped him up with a bear hug, making the 6-foot-7, 311-pound former offensive lineman look like an average-size human compared to his 6-foot-8, 250-pound frame, due to his ridiculous wingspan.
"Humbled," Thomas wrote on a retweet, featuring a video of the exchange.
Earlier in the day, Thomas had a farewell news conference, where he joked about the team's lackluster past.
"What he gave to that franchise, all the losing and for him to just be consistent every single Sunday, knowing that if there is one guy that is going to be in uniform, it's going to be Joe Thomas," James told reporters after the game. "Not only in uniform but every single snap. He's a legend around here thats for sure. He'll be in the hall very soon. The good thing is that he doesn't have to travel that far to be in the hall. It's right down the street."
Thomas is just 26 days older than James. He joined the Browns in 2007, while James joined the Cavaliers in 2003 after skipping college for the NBA Draft.
"Of course, something I will tell to maybe my kids some day is when I got to 10,000 straight snaps and [Cavaliers F] LeBron James tweeted at me," Thomas said Monday in his retirement speech. "Of course, when I retired, he tweeted at me again. I would like to tweet back at him some day. Hopefully, that is not for a long time because I still love watching him play."
He went on to talk about life as an NFL lineman, again referencing James.
"As a linemen, you always have this perception of yourself as a mushroom," he told reporters. "You are the guy, in the corner, who they keep in the dark room and they throw crap on him and they expect good things to happen. You just do not think of yourself as anybody that important. Over the last week to hear all of these, actually important, people like LeBron and other people really important, send congratulations and talk about what you have meant to them."
"I got so many messages on Twitter and through text messages and emails from people that I have played with, people who are in the NFL now who were maybe in high school or middle school when I started playing and they were talking about how they looked up to me, the way I played and the way I carried myself. That meant a lot to me, guys that are Pro Bowl tackles that I think are the next Hall of Fame offensive linemen in the game right now sending me messages and calling me, telling me what I meant to their career. Those were things that you never think about. To read those things, I can tell you, I went through a lot of boxes of Kleenexes over the last week."