And last night he came out and said he was gay.
Thomas revealed he had already told teammates and close friends about his sexuality - and had their support.
So why did the 35-year-old delay in telling people? Thomas said he had known he was gay since he was 16, but could not come out because of rugby's macho image.
He said: "Rugby was my life and I wasn't prepared to risk losing it."
Thomas is still playing, so this is a huge deal. I've often wondered myself if any US athlete will ever come out while they're playing. Statistical odds say there is a gay athlete in one of the major sports leagues. However, the incredibly macho nature of sports makes it pretty unlikely that they'd admit to being gay any time soon.
Anyway, I salute Thomas for what he did. That took a hell of a lot of courage.