How much can Dan Haren help?

Is there a dark side to being one of baseball's men of granite?

When lower-back inflammation knocked Dan Haren out of the Angels' rotation early this month, it wasn't only his first trip to the 15-day disabled list in 10 major-league seasons. His next missed start was his first. Since breaking into the major leagues in 2003, Haren had been out there every time it was his turn to pitch -- in two leagues, for four different teams.

Getting well while the team played on was a new experience for Haren and not fun.

"At the All-Star break, I had insomnia," Haren said. "I slept like nine hours in three days, total. I was just stressed about not being out there and I stayed home. That was really hard, watching the team on TV. Especially if you lose a game or two -- we lost that tough one (Friday) -- it's just hard not being there."

Now, with Haren on the verge of returning this weekend against the first-place Texas Rangers, the Angels -- suddenly short on pitching -- desperately need what he has always brokered in: reliability and quality. But what can they realistically expect?

Is there a price to be paid for pitching more than 1,800 major-league innings, practically without interruption? Pitching is a violent act. Inevitably, it wears down the ligaments, tendons and muscles inside a pitcher's arm. The art of counter-adjustment is the key to longevity for pitchers, but how far can you go with it if your arm isn't capable of generating the speed it once did?

Haren has secondary pitches that would be the envy of most fellow pitchers: a diving split-finger fastball; an effective cutter that can neutralize left-handed batters; the occasional breaking ball or changeup.

But while watching Monday night's rehab start for Class-A Inland Empire, you couldn't help wondering whether a gradual erosion in fastball velocity has been at the root of Haren's struggles. The difference between a 92-mph fastball and an 88-mph fastball has bigger consequences than dipping from 96 to 94, where it's all a blur, or 87 to 85, where losing velocity can actually help you. Haren hovers right around the speed limit, but he's more effective when he's at least pushing it.

Haren said his back felt great Monday and that he was ready to rejoin the Angels in time for an important series this weekend against first-place Texas. You can't question his heart or his devotion to his craft. Those are established.

But, according to the in-stadium radar gun, Haren's fastball was in the 87 to 88 mph range all game. According to a scout in attendance, the gun in San Bernardino was giving accurate readings. It showed that the opposing pitcher, a towering 21-year-old Padres right-hander named Matt Lollis, was reaching 95 mph in the early innings.

Maybe it was the setting: a single-deck stadium with a couple thousand fans, many of whom brought their dogs on "Man's Best Friend Monday." Haren had last pitched in a Class-A stadium in 2002, when he was 21.

"It was tough to get the adrenaline level up," Haren admitted. "With all due respect to these guys, it's not easy. The facilities aren't the best in the world, but these guys get by. They're not complaining. They love it. It was fun to be around them for a few days, but it'll definitely be easier pitching in front of 40,000 fans at Angel Stadium."

Many of those fans will be anxious to see how much Haren can help the Angels' struggling staff. They just shouldn't expect too much too soon.