Despite the struggles of Clay Buchholz, it's the bullpen that should most concern Red Sox fans

It's unwise to rely too heavily upon a rookie starting pitcher in the midst of a pennant race. Unlike the New York Yankees, which in spring training decided that a rotation featuring Phil Hughes and Ian Kennedy would allow them to contend, the Boston Red Sox did not originally lean on a rookie. With Josh Beckett, Daisuke Matsuzaka, Jon Lester and Tim Wakefield atop the rotation, there will little pressure on No. 5 starter Clay Buchholz. However, at this stage of the season with Wakefield on the disabled list and Bartolo Colon not ready to contribute, the Sox were hoping that Buchholz would respond under pressure as they chase Tampa Bay in the American League East and cling to the wild card lead.

At least for this year, the Buchholz experiment ended last night. After he was handed a 4-0 lead but coughed up five runs, three hits and three walks in 2.1 innings at Baltimore, the 24-year-old phenom was banished to Double-A Portland. Only half of Buchholz''s 60 pitches were strikes.

As it did recently when Texas scored 17 runs and Toronto plated 15 runs, Boston's bullpen imploded. David Aardsma relieved Buchholz and surrendered a three-run home run to Ramon Hernandez and later an RBI single to Juan Castro before ending the third inning rally. Javier Lopez and Mike Timlin were awful as well. Lopez permitted a three-run home run to Melvin Mora in an inning of work while Timlin allowed a run, a hit and three walks in two innings. Only Hideki Okajima, who tossed two innings of scoreless relief, could silence Baltimore's offense.

This loss was tough to absorb, especially since the Sox grabbed an early 4-0 lead and the Rays lost to the Los Angeles Angels. There is no doubt that Buchholz has a bright future in the big leagues, but it is unlikely he will return to Boston this season. With off days today and Monday, Terry Francona can skip the No. 5 spot in the rotation. Or, the Sox could recall David Pauley, who improved to 14-4 at Pawtucket with a win last night.

Pauley might be better suited for a relief role when rosters expand on September 1. Unlike most members of the Red Sox bullpen, Pauley throws strikes. Right now, only Jonathan Papelbon, Justin Masterson and Hideki Okajima have spots reserved in next year's bullpen. Manny Delcarmen and David Aardsma have nasty stuff, but they need a GPS device to find home plate. Javier Lopez is only effective against left-handers, and Mike Timlin should have been released earlier this season.

It may sound redundant to Sox and Pinstripes regulars, but there is no question that Boston's inconsistent bullpen is the main hurdle that could prevent the team from either reaching the post-season, or advancing into the ALCS or World Series. Tim Wakefield's rehab is proceeding well so far, and his return would give the Sox a rotation of Beckett, Matsuzaka, Lester, Wakefield and Byrd with Bartolo Colon (if he ever gets healthy), David Pauley and Michael Bowden as insurance. That is a formidable rotation.

In 2009, expect Boston to pursue another elite starter. Among the candidates are CC Sabathia, Ben Sheets and A.J. Burnett. Beckett, Matsuzaka and Lester are the anchors. It would be wise to bring back either Wakefield or Byrd, but not both. Since Wakefield is injury prone, perhaps Byrd would be a better No. 5 candidate. Since Pauley could be in Boston's bullpen next year, Buchholz, Bowden and left-hander Kris Johnson (who is at Double-A Portland this season) would serve as rotation insurance. If the Sox do not sign an elite starter, maybe it would be ideal to resign Wakefield and bring back Byrd.

As for the remainder of this season, Boston needs Beckett to get healthy and regain his ace form, Wakefield's should to recover and Byrd to give the team seven innings per start while allowing no more than three or four runs. Right now, it looks like the Red Sox will be limping to the finish line.