The 2009 Lions star is in the final year of his current deal with the Welsh region and is likely to attract attention from across Europe.
He capped his first start in six months with a try for the Blues in their 34-18 victory over Benetton Treviso on Saturday.
But the 44-cap Wales centre admits he has plenty to consider in a massive year, in which he also completes his medical studies.
"I haven't got a clue yet what I will be doing next year, whether I will be here or going," said the 25-year-old.
"Obviously, my contract is up and I finish my medical degree. There is a lot to be resolved and, hopefully, over the next few months, I will get that sorted."
The completion of Roberts' medical studies in Cardiff widens his rugby options. But he insists in an ideal world he will remain with his home club.
"It's quite an exciting place to be. I suppose, for the first time in my career, once I have finished my degree, I won't have any commitment with university work so, yes, it's a big crossroads," added the burly centre.
"What a player does is very individual and everyone has got different circumstances and they play a huge part in decisions.
"There is a heck of a lot to weigh up and it's a short career. I'm a Cardiff person through and through and hopefully I can be here."
One thing that is certain is Roberts' desire to secure a place on a second Lions tour.
Warren Gatland's men jet to Australia next summer and Roberts hopes to be part of the party. But he is well aware that the hard work begins with his region.
"It's quite a big year. The Lions is something I'm sure every player will be thinking about and desperate to go on, myself included.
"The only thing we can do as players is focus on every day in training and playing week-in, week-out to the best of our ability. The rest will take care of itself."