NEW YORK -- Kerry Wood once was Joba Chamberlain. He was the phenom that had a whole city hopping around because of the way his fastball lit up the night.
Wood flamed out as a starter before he reached his full potential in Chicago. His and Mark Prior's injury miseries with the Cubs were part of the precedent that the Yankees used in justifying the Joba Rules.
Now, Wood's arrival further signals that Chamberlain's future as a Yankee is in serious doubt. If Wood pitches up to his talent and stays healthy -- two big "ifs," especially the second one -- then Chamberlain becomes just another reliever at the end of the Yankees' bullpen.
Wood is not a sure thing by any means. He just came off the disabled list Saturday, recovering from a blister on his right finger. It was the 14th time Wood has been on the DL, which makes Nick Johnson look like Cal Ripken Jr. by comparison.
At this point in his career, the 33-year-old Wood is not a Joakim Soria, the Kansas City Royals closer who was the Yankees' first choice. Instead, Wood is a reliever with a big name but a small 2010 résumé. To go along with his two DL stints, he has a 1-4 record, a 6.30 ERA and eight saves.
On the plus side, he has struck out 8.1 batters per nine innings, which is very good.
Still, with Soria unavailable and no one else in his class on the market, the Yankees decided to add protection in case Chamberlain or David Robertson can't provide the bridge to Mariano Rivera.
Meanwhile, the Yankees picked up two other players to address general manager Brian Cashman's publicly stated goal of improving the bench along with the bullpen. Acquiring Lance Berkman and Austin Kearns gives the Yankees added depth at DH and in the outfield.
But all these moves have resulted in new (Curtis Granderson's future) and old (Joba's role, of course) questions to examine. So let's take a look at them.
WHOSE JOBA IS IT?
Chamberlain's time as an important Yankee might not be over yet, but four summers after setting New York on fire, his future is murky.
The Yankees searched for a top-flight replacement for him, which further indicates -- rightfully, we should add -- they don't know if they can trust Chamberlain anymore. Wood might be top-flight, but he is the Nick Johnson of relief pitchers and can't be fully counted on until he proves otherwise the next three months.
If Wood isn't up to the task, it appears Robertson will get a chance to be the new bridge to Rivera. Since June, Robertson has been very good -- holding opponents to a .232 batting average, resulting in a 2.29 ERA in nearly 20 innings of work. Chamberlain will have to scratch and claw to get his spot back.
Still looming over October, even with Wood onboard, is the Yankees' willingness, if necessary, to move All-Star starter Phil Hughes back into the bullpen.
An intriguing outside-the-box alternative, suggested by "Baseball Tonight" analyst J.P. Ricciardi before the Wood deal, would be to start Hughes in the postseason and have A.J. Burnett fill the eighth-inning role. If the Yankees think Burnett's psyche could handle that, his stuff for three outs toward the end of games could be Joba '07-like.
GRAND CLOSING?
The addition of Kearns illustrates that Granderson's struggles against lefties aren't cured. Granderson entered Saturday night's game batting .214 against lefties. If Kearns does his job well, Granderson won't get much of a chance to improve that number.
Kearns is a major upgrade defensively over Marcus Thames, and Gardner is a better center fielder than Granderson. The Yankees could shift Brett Gardner to center and put Kearns in left field against lefties.
The Yankees' disappointment in Granderson's struggles could have long-range ramifications. Granderson has a little more than $18 million coming to him over the next two years. In 2013, the Yankees have a $13 million option they can pick up, or they can decline and send Granderson on his way for $2 million.
With Gardner outperforming Granderson, Granderson's time in the Bronx may end before his contract does. It is a situation to watch going forward, because the way it works with the Yankees (and most other places) is, first you lose playing time, then you lose your locker.
Meanwhile, the right-handed hitting Kearns is known as a hard-working player. Though he has never lived up to the hype that preceded his arrival in Cincinnati eight years ago, he is a solid pro. The Yankees picked him up to play against lefties, but he has hit for a higher average this season against righties (.284 compared to .250). For his career, Kearns is slightly better against lefties (.261 to .256), and he has some pop, as evidenced by his eight homers in 301 at-bats this season.
HIP, HIP, JORGE'S KNEE
Whose at-bats is Berkman going to take? Could it be Posada's? The question probably only becomes relevant if Posada's knee injury seriously affects his ability to catch.
If Posada becomes more of a DH, then Berkman may have to sit a lot. The Yankees, under Cashman and manager Joe Girardi, run a meritocracy, so Berkman is going to have to earn his at-bats. One thing is certain: Girardi will still use the DH spot to keep Alex Rodriguez, Derek Jeter, Mark Teixeira and Posada fresh.
Berkman is a five-time All-Star, but at 34 he is not the same player he once was. He arrived with a .245 average, 13 homers and 49 RBIs on the season. His on-base percentage is still an impressive .372.
Thus far this season, Berkman is hitting .261 left-handed compared to .188 right-handed. Only one of his 13 homers has come hitting right-handed. With Girardi's penchant to lean on statistics, this likely means Berkman will play more as a left-handed hitter.
Andrew Marchand covers baseball for ESPNNewYork.com. You can follow him on Twitter.