So our long, national nightmare is finally over, with Mike Napoli inking a 1-year, $5 million deal that will make him a Boston Red Sox for the 2013 season. While some folks seem to be quite happy with the news, others are treading more cautiously – especially with news breaking today that during his physical a month and a half ago, Napoli was diagnosed with Avascular Necrosis (AVN), a degenerative disorder that kills bone tissue.

Mike Napoli

Hip looks good to me… (Credit: Julie Fennell)

For those of you not privy to AVN, it’s the same disorder that Bo Jackson was diagnosed with that prematurely ended his career. The track record for athletes with AVN isn’t good, but if Napoli’s got anything going for him, it’s the fact that doctor’s caught it early. This could be significant as Gordon Edes pointed out in his piece over at ESPN Boston last night – which pointed to there even being a possibility that Napoli could recover completely and never feel so much as a twinge, so long as the AVN is treated quickly.

While Napoli’s hip injury will be sure to hang over his head as the season begins, there’s little reason to think that it’s going to be much of a hindrance over the course of the year, at least in the short term. Napoli was pretty insistent that he has yet to feel any of the symptoms of his condition and while some people might chalk that up to wonton lip service, recent history suggests that he’s probably telling the truth. Not only has Napoli never been DL’d for hip issues in the past, but there wasn’t any indication that his hip was bothering him at all over the course of last season. In fact, September was his best month of the year as he posted a meaty .462 wOBA, thus ending the season on a high note.

However let’s make no mistake about it, losing $34 million is a big deal. It’s obvious that this condition increases the team’s risk substantially. However, considering the other options out there and the price at which they were able to snatch Napoli off the market for, then this is probably the best move they could make.

In fact, unless something changes dramatically, it’s probably best to proceed as normal and assume that Napoli should be fine for the season. The only question that leaves us with is what kind of player we can expect to see next season, bad hip and all.

What you see with Mike Napoli is – generally speaking – what you get. He has tremendous power, walks a lot and strikes out frequently. He’s an awful base runner and won’t likely bring much value with his glove at 1B. At the end of the day, an overwhelming majority of his value is derived from the power in his bat.

A lot of people have glowingly cited his performance at Fenway Park over the years as a reason he’ll do well here, but I’m not sure that’s necessarily a sure-fire thing – at least not in the way people think. It’s worth considering that in spite of his obscene 1.107 career OPS at Fenway, many have also pointed out that he’s got a .657 OPS at U.S. Cellular Field, which is even more of a hitter’s haven than Fenway. To me, the park effect on Napoli is PROBABLY a bit over stated and a victim of small sample size. Long story, short – don’t get carried away with it.

That doesn’t mean he’s not a good fit, it just means that we should recalibrate our expectations a bit.

The good news is that – as Eno Sarris pointed out on Fangraphs yesterday – Napoli is pulling the ball more, which with the extra bump from Fenway, should help his old man skills maintain themselves for a bit longer than others and hopefully mitigate some of his less than desirable ones. While Napoli might have a bit more trouble distributing HR’s to RF like he has in the past, he should more than make up for it by hitting line drives off the monster and racking up lots of doubles.

While I’m not sure Napoli is going to be a 25-30 HR hitter in Fenway this year, I do feel pretty confident that we’ll see a nice little spike in his doubles total and a decent bump in his batting average. The always-optimistic Bill James projections have him at .248 while a conglomeration of fans at Fangraphs collectively have him around .255. I think that’s probably a pretty fair range at Fenway, with 5-7 doubles tacked on for good measure, bad hip and all.

And something worth chewing on: In 2012, Napoli posted a 114 wRC+. Adrian Gonzalez coincidentally posted a 115 wRC+. Napoli also posted a better overall wOBA and SLG% and had a lower OBP by .001 points. I’m not saying Mike Napoli is Adrian Gonzalez, but it’s nice to be able to replace that kind of offensive production from last year at a 70-75% discount for 2013.

While there are risks of acquiring a player with Napoli’s condition, the price is pretty right here. With no track record of hip injuries, a lighter workload defensively and the medical team thankfully catching this early, the Red Sox shouldn’t have TOO much to worry about next season. While I wouldn’t double down and extend Napoli, I certainly wouldn’t pass up the opportunity they were afforded this year to sign him. He should be a good fit for 2013 and an important factor in the team’s overall success.