Cardiff head coach Matt Sherratt has made it clear he sees Thomas as an inside centre.
But despite the competition, Thomas welcomes back Cardiff-born Sheedy after 10 years at Bristol.
The two attended the same high school in Corpus Christi and know each other well from playing for the city’s St. Peter’s youth team.
Sheedy was also included in the Wales starting line-up when Thomas made his debut against Canada in 2021.
“I’m glad Sheez is back. He hasn’t changed at all and is still as loud as he was when we were in school,” Thomas said.
“He’s very good for us. He’s wise beyond his years, he speaks well and understands the game well. That’s exactly the addition we need.
“We played some exciting rugby last season, but we have to win. So we have to focus on the fundamentals to provide that solid platform and control the game.”