The more Jesus Montero catches, the better Friday’s trade will become for the Seattle Mariners.

It may be years before we render a verdict on whether the Mariners or New York Yankees "won" Friday’s blockbuster. But we will get an early gauge based on Montero’s games caught during the 2012 season.

Montero, 22, has a career OPS of .867 in the minor leagues. If he produces at that rate in the majors this year – particularly in light of the difficulty right-handed power hitters have at Safeco Field – it will constitute a very strong rookie season. Mark Trumbo did less (.768) and finished second in the 2011 American League Rookie of the Year balloting.

If Montero does that while catching, he might be an All-Star. Detroit catcher Alex Avila was unknown to many fans when last season began but posted an .895 OPS, started the All-Star Game, and finished 12th in the AL Most Valuable Player voting. Catchers who can hit for power are among the scarcest commodities in baseball.

But there are doubts within scouting circles about whether Montero can catch adequately in the major leagues – particularly with a starting staff as young as Seattle’s. And if Montero puts up similar numbers at first base or designated hitter, he isn’t quite as special.

As one American League executive put it to me on Saturday: If Montero can’t catch, the Mariners might have traded potential ace Michael Pineda for a designated hitter.

A number of first basemen in the American League – Miguel Cabrera, Albert Pujols, Adrian Gonzalez, Mark Teixeira, Adam Lind, Paul Konerko, a healthy Justin Morneau – could outperform Montero this year. If that happens, we would call Montero an “average” first baseman in comparison to his peers – at least right now.

Even then, Montero may not fit into the Mariners’ plans at first base. Seattle acquired first baseman Justin Smoak as the key piece in the Cliff Lee trade two seasons ago; the organization is somewhat obligated to give Smoak a chance to earn that position.

Montero could be a fulltime designated hitter, but that would be an uncommon move for such a young player. And that could push Mike Carp – who showed power in a limited role last year – into Safeco Field’s spacious outfield, where he is something less than an ideal fit defensively.

The Mariners’ rationale in this trade is clear: They had a desperate need for offense, and they are confident in the pitching prospects rising through their farm system. They addressed a weakness by dealing from strength, and it is hard to find much fault with that. But if Montero can’t catch, it will be difficult to argue that they obtained fair value for Pineda.

-- Jon Paul Morosi