The No. 4 ranked golfer in the world was part of the United States' seventh consecutive Presidents Cup win against the International team on Sunday.
Team USA beat the International team 19-11 in the tournament at Liberty National Golf Club in Jersey City, N.J.
After the final round, Thomas was an afterthought when he stood near Tiger Woods and Phil Mickelson. He stood in the background as the longtime rivals shook each other's hands and embraced.
Thomas stood behind them with his hand up in the air for a high-five.
He embraced the awkwardness after photos of the sequence surfaced on social media.
"I'll high five myself. It's fine," he wrote on Twitter.
"It was a blast," Thomas tried to say in the post tournament press conference, before being silenced and hazed by his teammates.
Woods was taking part in the tournament as an assistant captain. He explained that he has been friends with Mickelson for a long time.
"I think the press has made it out to be more than what it has been. We've been friends for a very long time," Woods told reporters, according to the Golf Channel. "We've had some tough moments where we've lost some cups, and also the flip side is we've had some great success. Hopefully, going forward, we can continue doing it."