Red Sox pitcher Curt Schilling has a significant, unspecified arm injury that could threaten his season, and possibly his career.

Schilling declined comment yesterday, but wrote on his blog, 38pitches.com, that he has agreed to abide by the club's request to rely on rest and rehabilitation.

"There have been disagreements these past few weeks in an effort to provide me with a solution that would allow me to pitch as much as possible during the 2008 season. At no time did I ever consider taking a course of action against the club's wishes. In the end, regardless of who agreed with whom, I have chosen the club's course of action and will vigorously pursue any and every option I can to be able to help this team to another World Series title in 2008."

Red Sox officials did not return calls for comment, but issued a statement that said: "Curt Schilling was examined by Red Sox doctors in January after he reported feeling right shoulder discomfort. Curt has started a program of rest, rehabilitation and shoulder strengthening in an attempt to return to pitching.''

The veteran right-hander did receive multiple cortisone shots in the arm last season, including one in October that enabled him to pitch in the playoffs. Prior to signing his contract in November, Schilling passed all the necessary physicals required by the team.

The 41-year-old recently met with Dr. Craig Morgan, the physician who performed Schilling's shoulder surgery in 1995 while a member of the Philadelphia Phillies. It's believed Morgan wants the pitcher to have surgery, while the Red Sox want to look at other options.

The Sox, however, have called into question the $8-million contract he signed last November.

The dispute over Schilling's treatment went far enough to lead him to consult with the players' union over his rights. According to a side letter to the collective bargaining agreement, the player has the right to seek a second opinion from his own doctor, but it's in dispute what happens when the team's doctor and the player's disagree on the treatment.

"I have been consulted by Curt and his representative," said Michael Weiner, a lawyer for the players association. "The Red Sox have no basis to take any action against Curt."

Schilling was limited to 24 starts in 2007 because of tendonitis in his right shoulder and spent seven weeks on the disabled list (June 22 to Aug. 6). When he returned to the rotation, he posted a 3-4 record with a 3.34 ERA in nine starts. During the Sox' playoff run to a World Series championship, he received a cortisone shot that helped him record a 3-0 mark with a 3.00 ERA in four starts.

Schilling talked last October of how he reinvented himself from a power pitcher to a finesse pitcher. Prior to the clinching Game Three of the ALDS in Anaheim against the Angels, Schilling said Josh Beckett pitched like a bazooka, Daisuke Matsuzaka was a machine gun and then called himself a sniper.

"I pick my spots and pick my targets and execute perfectly," he said.

He won that game, but was hammered by the Indians in Game Two of the ALCS. It's believed he received that cortisone shot around this time, after which he won Game Six of the ALCS and Game Two of the World Series.

Schilling has said 2008 would be his last in the majors, a prediction he has made in the past seasons but ultimately changed his mind and continued to pitch. No matter how this situation is resolved, Schilling will be in Fort Myers when pitchers and catchers report for spring training next week.

With Schilling on the shelf, Jon Lester and Clay Buchholz will have the opportunity to step in and help the rotation. It was believed with the Sox having an abundance of starters - Beckett, Matsuzaka, Schilling, Tim Wakefield and Lester - Buchholz would possibly start the season with the PawSox. But now that doesn't seem like the case.

Red Sox second baseman Dustin Pedroia learned of the situation at noontime yesterday while working out in Arizona.

"Obviously it's shocking," the reigning Rookie of the Year said. "Schill is one of those guys who, when he goes out there and pitches, he never shows weakness. If he's hurt, he goes out there and competes. He's the most overeducated pitcher. He goes out there, he has a game plan and he executes it. You can never tell if he's injured or what he's thinking and that's what makes him great. I hope it's not as serious as what's being written, so hopefully he can recover and help us out."

If not, Pedroia says the Sox' pitching staff has the necessary depth to be successful.

"But anytime you have a guy like [Schilling] who is out, because of what he brings to the table, it will be tough," Pedroia said. "We're going to have to overcome something like that. In this game, there are always injuries and always times in the season when you have bumps in the road."

Still, Pedroia is hoping Schilling will be able to pitch this season.

"With everything he's battled in the past, nothing surprises me with Schill," said Pedroia. "He's Superman and I wouldn't put anything past him."