Conor McGregor announced his retirement last night via his Twitter account. Here's what he wrote.

The announcement is likely a negotiating ploy. Just hours before his retirement tweet, McGregor, appearing on "The Tonight Show Starring Jimmy Fallon," said he was in contract talks for his next fight. He said that bout  would probably in July.

Here's Fallon's interview with McGregor. He talks about fighting at the 5:52-mark.