It’s not apples to apples, but there are some interesting similarities.
While we can assume Mike Napoli’s hip should be of some concern — hence the agreement to knock down a three-year, $39 million deal to potentially one year at $5 million — there isn’t any certainty regarding the extent of the ailment. When it came to Mike Lowell , on the other hand, there wasn’t much mystery. The former Red Sox  infielder had a torn hip labrum that eventually led to his retirement.
And while Napoli  has spent the majority of his career as a catcher, Lowell’s primary position was third base.
Yet, in the end, you do have two players who found themselves transitioning to a role in which they primarily played first base while dealing with a hip issue. And that is where the paths converge.
“I think in my case I was probably going to move more than playing third base, but the moves would be easier,” Lowell said from his Miami-area home. “You have to cover first on every ground ball, but you really don’t come in on ground balls so I viewed it being easier at first in terms of mobility.
“In regards to Napoli, I have no idea what his hip injury is. If it’s something they saw in an X-ray or an MRI that could hinder him, or could happen, that’s so arbitrary. You might need surgery in five years, but I can see the Red Sox protecting themselves if he needs it in three months. I can see where playing first is much less grueling for Napoli than catching. From that standpoint it will keep him a lot fresher and keep his offense, which is what he’s being signed for.”
When Lowell was moved to first base for the 2010 season, ultimately playing 43 of his 73 games at the position, he had the advantage of having already lived the life of a corner infielder. Napoli, by contrast, has primarily been behind the plate, though he enters his role as a Red Sox first baseman with greater experience at the position than did Lowell, having played 69 games there in the minors and 133 in the majors (starting in 2010, when he played 70 games at first base).
The move from backstop to first base is hardly ground-breaking, with players such as Carlos Delgado , Victor Martinez  and, more recently, Joe Mauer  also making the switch. But baseball folks will tell you the alteration is often much more palatable if there is some history of playing an infield position, as was the case with Martinez, who came up as a shortstop.
And even for Lowell, the move took some time. There was less need for mobility, but there were perhaps more intricacies than even third base presented. The former Red Sox does explain, however, that Napoli might have a leg up because of the attention to detail his former position demanded.
“I would say there’s definitely an adjustment,” Lowell said. “Comparing my situation to him, I think there’s less of an adjustment going from third to first because you do see similar ground balls. But I think to handle a staff as a catcher is much more complex and detailed than playing first base. So from the capacity of knowing where he needs to be at what time, it will take him two days. He’ll be fine. Then I just think it’s a matter of getting reps. That’s what spring training is for. He’s not going to a position that is totally foreign. If this is going to be his primary position than he can take all of his reps at that position and the improvement will be big and the consistency will come quickly.
“Is he going to turn into a (three-time Gold Glove winner) Derrek Lee? I don’t know. But he is going to get a lot better than what he is.”
While it does feel like the Red Sox are willing to deal with Napoli’s development at first base in exchange for what is perceived as middle-of-the-order offense, the importance of having a capable defender at first shouldn’t be understated. It was part of the package that made players like Mark Teixeira  and Adrian Gonzalez  so attractive during the Sox’ pursuits of the pair.
“I do believe it’s undervalued as a position from the defensive perspective,” Lowell said. “But if you have a guy who can’t move around well, that’s probably the only place you can put him.
“If your infielders throw everything at the chest, then you probably can get away with someone who is subpar. Of all the positions, first is the place you can put somebody with the least mobility. That said, put a regular guy who has never played first in there, compare him with Mark Teixeira and you’re going to see how many runs a Teixeira will save picking balls out of the dirt, you’re going to see his range, throwing to second to get the lead runner ‘¦ Most guys can probably get in front of the ball, knock it down and either go to first or flip it to the pitcher. But it’s the 10, 15, 20, 25 times during the season where the guy picks the ball out of the dirt or gets the ball down the line because he has range.
“I think everyone was willing to say [Miguel] Cabrera ‘s offense was going to outweigh his lack of range. But to everybody’s surprise his range wasn’t bad, so that trade-off was worth it. With the numbers Napoli puts up in Fenway, there’s a little bit of that to it.”