Roberts will join Super Rugby side Stormers from Bath when he flies out to Cape Town next week.

The 33-year-old was not named in Wayne Pivac's 38-man Six Nations squad, but has not given up hope of a recall.

"I told him I'm only one flight away if someone goes down," said Roberts.

The centre has played three Tests for the British and Irish Lions and won 94 caps for Wales with his last international appearance coming in November 2017 against New Zealand.

Roberts has revealed Pivac phoned him to outline his selection decisions.

"Wayne called me and we had a good chat where he told me where he was at and I have huge respect for him," said Roberts.

"I still harness ambitions to play Test rugby and feel I'm good enough. I'm ready to go, I've played quite a bit of rugby this year with Bath.

"So if that call comes I can be on a next flight out of South Africa because that has always been the most important thing to me.

"I am gutted not to be included in the original squad but I am excited to see the youngsters involved.

"There are some old heads in there, a lot of experience, but I am absolutely delighted for the young uncapped lads who get their first shot at Six Nations rugby."

Tompkins 'packs a punch'

One of the five uncapped players in the squad was Saracens centre Nick Tompkins who played for England Under-20s but qualifies for Wales through a Wrexham-born grandmother.

With Jonathan Davies and Willis Halaholo ruled out of the Six Nations through knee injuries, Tompkins is one of only three specialist centres in the squad alongside Hadleigh Parkes and Owen Watkin.

"He's a top player," said Roberts.

"I've played against him a few times and he has massive growth potential. Wales see him as a 12 and 13, he is quick and elusive and he packs a punch.

"He has all the skills and he features heavily in a top side in Saracens this season and he has all the tools to make it at Test level.

"I know we have a bit of an injury issue in the midfield and he is a guy who is playing top level rugby in the Premiership this season.

"So he will take to Test rugby like a duck to water."