The term “gatekeeper” usually has a bad connotation in combat sports.
To be one, it means regularly being on the cusp of greatness – but also regularly just short while someone else goes on to, in this case, a middleweight title. So to get to that point to begin with: Very, very good. But most fighters don’t want that label saddled on them.
And Brad Tavares (20-8 MMA, 15-8 UFC) no doubt would prefer to ditch the term, too. But if that’s the word you have to describe where he’s at right now in his UFC career, ahead of a fight against Gregory Rodrigues (14-5 MMA, 5-2 UFC), so be it.