Oakland A’s first baseman/left fielder Mark Canha is off to a fine start to the 2015 season. Through the year’s first week and a half, he’s hitting a solid .333/.353/.515, and leads all rookies with 11 hits. This is obviously a teeny tiny sample, and we all know better than to read too much into seven games. But even so, an excellent performance from a previously unknown player is a little hard to ignore, especially after his six homers and .297/.342/.635 batting line from spring training. The A’s have to be happy with the return they’ve gotten on their rule 5 choice so far.

Although this is his first taste of big league action, Canha’s no youngster. He turned 26 this past February, and has been playing professionally since 2010, when the Marlins drafted him in the seventh round out of the University of California. Although he started out as a 21-year-old in short-season ball, Canha moved through the Marlins system relatively slowly. He spent a full year at each minor league level, so he’s just now making it to the big leagues.

Canha’s slow climb up the minor league ladder wasn’t due to a lack of hitting. His wRC+s from 2010-2014 were 139, 144, 128, 141 and 131. He’s never hit worse than his league’s average, nor has he come particularly close. But, year after year, the Marlins chose to let Canha mash as an old-for-his-league slugger instead of challenging him with more polished pitching.

Last year, Canha his .303/.384/.567 in Triple-A New Orleans, which was one of the best performances in Triple-A last year. Yet despite his hot hitting, the Marlins opted to keep Canha in the minors for all of last season. These are the same Marlins who gave 150 first base starts to the dynamic duo of Garrett Jones and Jeff Baker, who combined for -0.4 WAR as first basemen. Canha didn’t even get a look in September. Instead, the Marlins called up Justin Bour — another first baseman, who’s nearly a year older than Canha.

Clearly, the Marlins never thought much of Canha, which is why they chose to leave him unprotected in last winter’s rule 5 draft. But as they say, one man’s trash is another man’s treasure. Canha was little more than an afterthought for the Marlins organization, but Billy Beane and the A’s apparently saw something more in the San Jose native.

KATOH seems to side more with the Marlins on this one. My system gives him a 72% chance of cracking the majors, but just a 6% chance of racking up more than 4 WAR through age-28. It essentially views him as a bench bat or an up-and-down player, and pegs him for just 1.8 WAR through age-28.

As much as I love KATOH, I’m not sure how useful it is for players like Canha. KATOH was designed to evaluate prospects, but Canha isn’t exactly a prospect. As a 26-year-old rookie, he’s probably more or less reached his upside, so it’s probably more sensible to focus on what he’ll do this year, rather than trying to speculate on his long-term future. Plus, it feels a little circuitous to use a model that considers players of all ages in order to forecast how a 26-year-old will perform through age-28.

Instead, let’s try to zero in on the Triple-A to MLB transition for players of Canha’s ilk. Below, you’ll find a list of players aged 28 or younger since 1990 whose league-adjusted walk rate, strikeout rate, BABIP, ISO and stolen base frequency fell within .5 standard deviations of Canha’s marks from Triple-A last year. I included columns for WAR and wRC+ so you can see how they performed in the majors the following year.

Pretty uninspiring. On the aggregate, this analysis generally agrees with KATOH on Canha: He’s good enough to merit a few big league at bats, but unlikely to do a heck of a lot with them. Despite posting strong Triple-A numbers, most of these guys received little or no big league playing time the following year. There were a couple of players who got legitimate shots and ran with them. Paul Sorrento turned in a 118 wRC+ in nearly a full season’s worth of games with the 1992 Indians, and went on to have a respectable big league career. Jack Voigt — now a hitting coach in the Mets organization — also hit well when given the opportunity, although he quickly faded into obscurity shortly thereafter. However, these two cases seem to be exceptions to the rule. Most of the Canha-esque players went nowhere the following year.

Steamer and ZiPS, which take into account his minor league performance and also his hot start in Oakland, also have tempered expectations for Canha. Both systems think he’ll be roughly a league-average hitter from here on out. That’s not terrible in a vacuum, but coming from a player near the bottom of the defensive spectrum, is probably worth less than a win over a full season. ZiPS’s top comp for Canha was Jeremy Slayden. I have no idea who that is, and neither should you.

Canha can hit a little bit, but he doesn’t stand out in any of the areas that wouldn’t show up on his offensive stat line. For one, he’s never had much of a platoon split in the minors, so he likely won’t add much value as a lefty-mashing platoon partner for Ike Davis. He’s also pretty poor on defense. Most of his minor league experience has come at first base or left field, which are two of the least premium positions. He doesn’t seem to play these positions particularly well, either. According to Baseball Prospectus, he’s posted negative FRAAs in each of the past three years.

So that’s Mark Canha. He’s a bat-only player, whose bat is only mildly interesting. For the time being, he’ll continue to get semi-regular playing time in Oakland, but it’s unlikely that he’ll do enough with the bat to provide much value net of his defensive shortcomings. He was almost certainly worth the $50,000 the A’s paid for him in the rule 5, but that’s not really saying much. Despite his excellent spring and hot start to the regular season, Canha has the looks of a humdrum, backup first baseman.