If you're talking about hockey and someone keeps trying to mention football, you might describe their comments as irrelevant. Irrelevant means not related to the subject at hand.

If a rock star becomes irrelevant, it means people are not relating––or even listening––to his music anymore. It isn't part of what people are thinking or talking about. The opposite is relevant, meaning related. An analysis of brush strokes in Manet's painting would be relevant to a discussion of texture in painting in general. Relevant was borrowed from Medieval Latin relevare "to bear upon," from Latin, "to lift up." The prefix ir-, meaning "not," is a variant of in- before words that begin with the letter r.

Definitions of irrelevant
  1. adjective
    having no bearing on or connection with the subject at issue
    “an irrelevant comment”
    irrelevant allegations”
    digressive, tangential
    of superficial relevance if any
    extraneous, immaterial, impertinent, orthogonal
    not pertinent to the matter under consideration
    inapplicable, unsuitable
    not capable of being applied
    of no legal significance (as having been previously decided)
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    having a bearing on or connection with the subject at issue
    capable of being applied; having relevance
    relevant and appropriate
    having precise or logical relevance to the matter at hand
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