Stacking the top of the leaderboard of center fielders is relatively simple because The Best Player on the Planet is at No. 1 -- that would be Mike Trout, of course -- and Andrew McCutchen is a solid No. 2 pick.

However, one evaluator who was asked for his input said there may be an intruder in the world of Trout and McCutchen very soon, because of the progress of Arizona’s A.J. Pollock. "I don't think a lot of fans and media understand how good he really is," the evaluator said.

The Diamondbacks certainly do, which is why they intend to follow up on discussions about a long-term deal with him later this winter, once other significant winter work is completed and Arizona begins to prepare for arbitration. Pollock will turn 28 Saturday, has a little over three years of service time and is coming off a season in which he compiled 65 extra-base hits, 111 runs and 39 stolen bases.

When Arizona has asked other teams about possible deals for pitching, Pollock's name has been mentioned repeatedly, and the Diamondbacks quickly deflect. "We aren't going to trade him," one Arizona official said.

Pollock is almost untouchable, Diamondbacks CEO Derrick Hall said Wednesday night.

Ranking the top 10 center fielders in MLB:

1. Mike Trout, Los Angeles Angels

He just had his 24th birthday in August, and yet sometime during the 2016 season, he'll probably hit the 150th homer of his career and score the 500th run, and by season's end, he'll be closing in on 1,000 hits. That is nuts. He is the only player in history to finish first or second in the MVP voting in each of his first four seasons.