KANSAS CITY, Mo. — The starting rotation is better and deeper. The prodigal closer has returned to his customary spot at the back end of the bullpen. The lineup features a new leadoff hitter and improved protection for the middle of the lineup.

But as the Red Sox begin their 2007 season here this afternoon, they’re not a perfect bunch. For the Sox to end the New York Yankees’ decade-long dominance at the top of the American League East, some questions will first have to be answered.

Here are five of them:

•1. Will the bullpen bounce back?

Jonathan Papelbon’s return as closer has solved the biggest issue – the ninth inning – but more than ever, bullpen depth is essential. Four of the Red Sox’ principal set-up men – Mike Timlin, Brendan Donnelly, J.C. Romero and Joel Pineiro – are coming off disappointing seasons.

Timlin had an ERA over 6.00 after the All-Star break and was sidelined the entire spring with an oblique strain. Donnelly and J.C. Romero were cast away by the Los Angeles Angels of Anaheim and Pineiro, having pitched himself out of the Seattle rotation, was non-tendered by the Mariners.

Of course, relievers are, almost by definition, inconsistent. Still, for the Red Sox to succeed, the majority of theirs will have to rebound. Having Papelbon to preserve ninth-inning leads won’t mean much if the bullpen can’t protect the lead in the seventh and eighth.

•2. Can Jason Varitek bounce back offensively?

Varitek remains invaluable as the team captain and handler of the pitching staff and his skills will be tested as never before as he guides Daisuke Matsuzaka through his first season.

But the Sox need Varitek to contribute offensively, too, if only to stretch out the batting order some. One through five, the Red Sox lineup as is strong as any in the game, but if Varitek and Mike Lowell don’t produce, the Sox won’t wear down opposing pitching staffs the way they did from 2003-2005.

Particularly in the last two months of the season, Varitek was nearly an automatic out and had difficulty making regular contact. Both he and the club maintain that his worst season since becoming the No. 1 catcher was the result of injuries (lower back muscle pull; knee) and the demands of the World Baseball Classic. For the Sox’ sake, they’d better be right.

•3. Will Coco Crisp have a better second season with the Sox?

Crisp’s 2006 season was compromised by a broken finger which took place in the fifth game of the year and caused him to miss two large chunks of the schedule. Even when he played, Crisp’s swing was slow and he seemed to have lost his aggressiveness.

Lowered to the bottom third of the order after the signing of shortstop/leadoff hitter Julio Lugo, Crisp no longer has on-base responsibilities that come with hitting first, a role for which, in retrospect, he was ill-suited.

This spring, Crisp’s bat speed seemed to have returned, allowing him to hammer even the best of fastballs. Also, situated at the bottom of the order, Crisp will be able to run more, freed of the worry that he might run into an out in front of David Ortiz and Manny Ramirez.

If Crisp plays well and reestablishes his value, the Sox could deal him next winter and install Jacoby Ellsbury as their center fielder next April. If he falters, they’ll likely go with Ellsbury anyway, but be forced to eat the remainder of Crisp’s multi-year deal.

•4. Does Dustin Pedroia have what it takes?

The Sox are doing the right thing by having Pedroia hit ninth, where he’ll feel little pressure, but there are scouts who question his game. For a diminutive player, Pedroia has a long swing with a tendency to uppercut, a bad combination for someone without much power.

Pedroia has exceeded expectations at nearly every level, but has often struggled initially. The Sox have to hope that last September, when he hit just .191, qualifies as his learning curve.

If not, will the Sox have the patience to stay with him? And will they rue their decision to pass on Mark Loretta’s offer to return for just $1 million?

•5. Can J.D. Drew stay healthy — and out of the cross-hairs?

Before he has even had an at-bat in a regular season Red Sox game, Drew sports a target on his back. Fans have been conditioned to believe that he’s injury-prone and without passion. The former seems undeniable — he’s played 140 or more game just twice in his career — but the latter label may be patently unfair.

If Red Sox fans are expecting a demonstrative, emotional player in the model of his predecessor, Trot Nixon, they’ll be sorely disappointed. Drew plays the game smartly, but under control. Off the field, he’s quiet and not one to lead.

But Drew is a better run producer than Nixon, to say nothing of a better outfielder and better baserunner.

It’s imperative that he get off to a good start. Otherwise, the rush to judgment is likely to intensify.

smcadam@projo.com