There are a number of storylines relating to the Twins that will increasingly come into focus as we edge toward spring training. The answers to a handful of important questions will play a large part in dictating whether the season is a success or a failure. Will Tsuyoshi Nishioka be able to effectively transition his game from Japan to the States? Will Joe Nathan be the same dominant late-inning reliever he was prior to surgery? Can Francisco Liriano blossom into one of the league's premier aces?

All players worth following. But to me, no storyline looms larger than the recovery of Justin Morneau, who hasn't been able to comfortably swing a bat since sustaining a concussion on July 7 of last year. If Morneau experiences another setback in spring training or takes any kind of bump to the head while on the field, the Twins will be facing the very real possibility of having to play without him for an extended period of time.

Up until this week, the front office had done little to address such a scenario. But on Friday, the Twins announced that they'd reached agreement with Jim Thome on a one-year, $3 million deal. The contract, which includes incentives based on playing time, ensures that a great bat from 2010 will be back in the mix this year, and also supplies the Twins with some Morneau insurance.

As great as Thome was last year, he's not necessarily an ideal fit. He's 40 years old and incapable of playing any position, which limits flexibility in an already suspect bench. He's a left-handed hitter who's weaker against southpaws, so if Morneau's healthy Thome does nothing to offset the Twins' vulnerability to lefties at the DH spot. (This was an issue many fans were pointing their fingers at after the Yankees took a two-game ALDS lead on starts from CC Sabathia and Andy Pettitte.)

Of course, those concerns are secondary when you consider the price. It's impossible not to like this signing at the terms the Twins were able to get. Thome is guaranteed only $3 million, which is a pittance for a player who became one of the league's best hitters upon stepping into regular duty last season.

After Morneau went down on July 7, Thome batted .303/.438/.669 with 15 home runs and 31 RBI in 50 games. His production was a key reason the Twins were able to handily lock up the AL Central despite losing their best hitter amidst an MVP-caliber season.

That performance, along with his excellent clubhouse rapport and tremendous fan appeal, has already earned Thome his 2011 salary, in my mind. As a fan, it's always more enjoyable to watch a player who truly likes being here. This was evident in Thome's demeanor last season and in the fact that he reportedly turned down at least $1 million from Texas to return to Minnesota. He's a class act and it will be a pleasure to watch him blast home run No. 600 -- only 11 more to go -- in a Twins uniform.

As a bench bat, Thome will be a godsend for a group that features Drew Butera, Matt Tolbert and Jason Repko. But there is room for concern over what will happen if indeed Morneau -- or Michael Cuddyer or Jason Kubel, for that matter -- should go down and force Thome into regular duty.

One can't realistically expect the Hall of Fame slugger to repeat his spectacular performance from last year. It was one of the top five seasons of his career, and duplicating that at age 40 with a balky back could be an impossibly tall order. One miraculous season for an aging star does not promise another -- just ask Brett Favre.

I've noted before that the track record for historically elite sluggers after turning 40 is not particularly pretty. Even the all-time greats tend to decline swiftly at this age. Then again, there wasn't much precedent for what Thome did last year, and he claims his back is feeling good, so why doubt him? He might not be ideal in terms of balancing the roster, but he's a great hitter and a great guy at a bargain price. I've got a lot more peace of mind now than I did a week ago when it looked as though he might be leaning toward the Rangers.

That peace of mind came in handy this weekend as I read the final paragraphs of a Joe Christensen story updating progress of Morneau's recovery:

I can't help but be troubled by what Smith was trying to frame as a positive update on the first baseman's condition. It indicates that, more than six months after initially sustaining his concussion in Toronto, Morneau still has not shaken symptoms. I'm not distrustful of the team's doctors, but it does strike me as a bit of a slippery slope advising Morneau to "work through" his symptoms -- this is a brain injury, not a sprained ankle. I'm sure that ultimately they'll exercise appropriate caution, as they have all along in this process.

Should worse come to worst with Morneau, it's comforting to know that the team now at least has someone on the roster capable of making up for even a fraction of that missing power production. In the best case scenario, Thome will serve as a late-inning weapon on the bench and occasional DH. For those purposes, you couldn't ask for a better hitter -- or person -- than a man who will soon become the eighth in major-league history to reach 600 home runs.

*** For some quick additional reading, check out this article from the ESPN.com Stats & Info Blog on the historical significance of Thome's numbers against right-handed pitching. You might be surprised by how high he ranks.