Flanagan's promoter Frank Warren is keen to strike a deal with Crolla's representative Eddie Hearn for a unification bout to take place later in 2016, but Gallagher has said that Flanagan is not Crolla's only option.
Linares, the WBC champion in recess, is currently out injured but Gallagher has said that a showdown against the Venezuelan in Las Vegas or at Old Trafford appeals more to his fighter than a domestic clash with Flanagan.
Gallagher told Sky Sports News: "You can see the appeal in Anthony. The atmosphere at the arena was fantastic and everybody in America has sat up and took heed of Anthony Crolla. He's gone to another level now.
"That fight against Flanagan would be fourth or fifth option. He's got two fights being put to him at the moment so that's not one that's up there. A Las Vegas night against Linares is one and Old Trafford is another. Those two nights are before anything else.
"The profile Anthony has is mainstream now. They all know who he is and he's one of the success stories of 2016. That's why I feel Crolla vs. Flanagan won't happen for another 12 months because nobody knows who Flanagan is so how can you sell it?"
Crolla successfully defended his world title with a seventh-round stoppage of Ismael Barroso on Saturday night.