Juan Portes has had a very hot start to spring training. With only 10 plate appearances, he leads the team with three home runs. So the question is "Is he for real?". The answer is probably not. (obviously not, if you are talking about hitting 3 home runs in ever 10 plate appearances.) Despite being taken in the 14th round, Portes has always been a pretty good hitting prospect. His problem is that he doesn't have a position. He has moved around the infield and seems to be considered an outfielder now. But if the only position he really has is next to the plate, its tough to make it to the big leagues as a hitter.
Jason Kubel is a good example of why young players rarely break in as DH's. It usually takes close to a 1000 major league at bats before a player settles in and is productive. Kubel didn't become primarily a DH until 2008 with over 750 plate appearances. And he still has played the outfield about 50 games each year while primarily being the Twins DH. You have to be able to play the field initially in order to get the major league at bats to prove yourself as a hitter. Contending teams just don't usually hand the DH spot to unproven rookies - in fact, no team does.
Of course, if Portes hits well enough, some team will find a way to get him in the lineup. But "well enough" is not they way Jason Kubel hit to start out, it means busting out of the gate with Kubel's numbers from last year. That is tough for a player to do. Portes may be a guy who does, but more likely he will remain a spring sensation.
The other thing to remember about spring training is that, in most games, there are really two games. The first half of the game the regulars play against one another. Then the second game is when prospects, who are likely going to start the season in the minor leagues, relieve the regulars and play against one another. I haven't looked at who Portes faced, but it is likely those home runs weren't hit off major league pitching. Certainly not the quality of major league pitching he would face starting in April. That is another reason why spring training results don't tell you much - at least not until the last week or so.
I like Portes and have wondered when we might see him break out. But, absent a position, he is likely to remain one of those guys who tantalizes us as fans with his numbers at AAA.