Roberts has played 96 international matches for Wales and the 30-year-old is chasing a century of caps with his national side.
He says he is very focused in getting back into the starting XV, after spending the vast majority of last season on the bench.
"I've got to get in the squad first. It's a competitive position," he told BBC Wales' Scrum V programme.
Roberts had been first choice for seven years, but lost his palace in the side after a 32-8 defeat by Australia in November 2016 and has not regained it since.
However, he's determined to represent his country again, as he added: "I think not many make it to 100 caps, but I'm very focused on the here and now and really delighted to get a couple of caps in the summer and really attacked this pre-season."