Tavernier – a Leeds fan – was at Elland Road last month to watch younger brother Marcus in action for Middlesbrough.
But he opted to sit among the home supporters instead of cheering on his sibling.
“I’m delighted and really proud of Marcus,” Tavernier, who came through Leeds’ youth ranks before leaving in 2008, said.
“He got chucked into the deep end at 18 for his debut.
“Boro had three wins on the bounce, and he got the winning goal against Sunderland in the derby. I was so delighted for him.
“I went down to watch him play against Leeds — but that was a bit of a hard one for me because I’m a Leeds fan and was sitting in the Leeds end!
“When I told Marcus I was going in the Leeds end I think he expected it because he knows what I’m like with Leeds.
“My mum wasn’t in the away end at Elland Road either as she’s a Leeds fan too.
“I told him I didn’t think I could stand in the Middlesbrough end getting shouted at by Leeds fans.
“But then again I was almost supporting Boro because of him.”
Marcus, 18, made his senior debut in August and has gone on to establish himself in Middlesbrough’s first-team squad.
“I’m really proud of him because he got his head down and has been working really hard,” Tavernier told The Scottish Sun.