Time for Justin Upton to start dominating

Who is Justin Upton?

Is he a good player? An All-Star right fielder? A guy who will be mentioned high on MVP ballots during his good seasons? Or is he going to be that superduperstar?

Upton teased us when he reached the majors at age 19 in 2007. In 2008, spending most of the season at age 20, he tantalized us with his talent, posting an .817 OPS and hitting 15 home runs. In 2009, he hit .300 with 26 home runs and looked like a guy who could become the best player in baseball ... or close to it.

He had a terrific season in 2011, hitting .289 with 31 home runs, leading the Arizona Diamondbacks to the NL West title and finishing fourth in the MVP vote.

And yet ... this is unfair, I admit ... I'm left wanting more. It's the curse of potential, I suppose, the burden of being so good when so young. Hall of Famer Eddie Mathews hit 47 home runs when he was 21 and spent the rest of his career trying to match that. Even though he became one of the greatest third basemen of all time, while still active many viewed Mathews a disappointment, viewing him through that age-21 lens.

I find myself doing the same thing with Upton. His batting line in 2009 was .300/.366/.532; in 2011, .289/.369/.529. Nothing wrong with that, of course, but we generally expect improvement from age 21 to age 23. Maybe a few more walks, a little more power. Upton, while terrific, was essentially the same player at the plate.

Entering 2012, the question still hovered out there: Could he get better? Could he put up a Matt Kemp-Ryan Braun type of season?

Then he suffered a nagging thumb injury and didn't homer or drive in a run in his first 13 games. Upton hit his third homer on May 2, but then went another 13 games without a home run while driving in just two runs, before finally snapping out of that slump with a game-winning homer off Colorado's Rafael Betancourt last week.

One problem plaguing Upton has been called third strikes -- he's taken 20 of them, which leads the majors. He struck out looking 35 times last season. Maybe the thumb is still bothering him, and he's tried to compensate by drawing more walks -- his walk rate is up 3 percent and he's swinging at fewer pitchers outside the strike zone. Maybe that approach means the home runs will start coming in bunches.

Or maybe he's just in a funk. His teammates certainly are.

Arizona is 19-24 after losing 6-1 to the Dodgers on Monday night, putting the D-backs 10.5 games behind the Dodgers already. The D-backs are ninth in the NL in runs scored, 12th in home runs, ninth in OPS. Other than Chris Young, who just returned from a DL stint, most of the Diamondbacks are struggling. Cleanup hitter Miguel Montero has two home runs. First baseman Paul Goldschmidt has just two bombs as well. Third baseman Ryan Roberts is hitting .227 with two home runs and a .288 OBP. Willie Bloomquist is Willie Bloomquist. Upton is hitting .235/.344/.353.

It's certainly an offense desperately in need of Upton to get hot. They need him to go on a tear like last June and July, when he hit .355/.424/.636 from May 30 through Aug. 2. He's the guy this offense feeds off of. He's what Kemp is to the Dodgers or Joey Votto is to the Reds.

So ... who is Justin Upton? Is he the guy who can carry an offense? Is he great player capable of an MVP season? Or is he an MVP player?