The Harlequins back, who will move to Bath at the end of the season, did feature for his country during the autumn internationals after a plethora of injuries to the backline.
However, the 31-year-old was omitted from Warren Gatland's party for the recent Six Nations despite a lack of experience at center, with the Kiwi coach rotating between Hadleigh Parkes, Scott Williams and Owen Watkin as his midfield options during the tournament.
With Jonathan Davies still to factor in when he returns from injury, Roberts looks to be facing an uphill battle to recover his place in the Wales squad before next year's World Cup in Japan.
Roberts is hoping to finish the Premiership season with a flourish in the hope of being part of Wales' summer tour when they will face South Africa in the United States before heading to Argentina for a two-Test series, believing he still has something to offer on the international stage.
He told Sky Sports News: "I've been told the door's not closed and if that's still the case I'll fight tooth and nail to get involved with Wales again, especially in a World Cup year.
"The World Cup is an amazing tournament to play in and is something I'll strive for over the next 12-16 months.
"I still want to play Test rugby and didn't want to rule that out, especially in a World Cup year. In a few years we'll readdress, but I'm really happy with the move to Bath.
"Do I still feel I'm getting better as a player? No doubt and that's one of the reasons for moving clubs.
"Sometimes a fresh group of players and coaches can reap its rewards. I'm looking forward to that. Hopefully a new environment will reinvigorate me."