Trainer Virgil Hunter feels Amir Khan needs to commit to the United States full-time if he is to become a world champion again.
Khan had his first fight on British soil in two years on Saturday in Sheffield when he overcame a knockdown to post a unanimous, if narrow, points victory over Mexican fighter Julio Diaz.
The 26-year-old is now targetting a rematch with Danny Garcia, who knocked Khan out in the fourth round of their WBC light-welterweight title fight in July 2012.
But Hunter says Khan must spend more time around his San Francisco training base if he is serious about getting himself back among the sport's elite fighters.
Hunter said: "I'm convinced now that in his own mind Amir knows he's got to work more and come to the gym more, and that he can't just go off between fights.
"Amir has to acknowledge that right now he is at a disadvantage because of the distance between us.
"I see Amir for three months when he comes over here, so the opposition can creep ahead of you because all the top fighters are with their trainers all the time.
"It is something we are going to work on to see if we can bring him up to the level we need him to be at."