OAKLAND -- The second line of Esteban Loaiza's biography in the A's media guide calls the 34-year-old right-hander "one of the top free agent bargains among the free agent pitching class of 2005."

After Loaiza went 12-10 for the Washington Nationals in 2005, despite laboring with some of the worst run support in the NL, Oakland landed him with a three-year deal (with a club option for the fourth year) that will pay him $6 million this season.

So far, the investment hasn't paid off. Loaiza, scheduled to pitch on Tuesday in the series opener against Detroit, has not made it through five innings in either of his first two starts, and has allowed 24 baserunners in 8 2/3 innings while going 0-2 with an ERA of 11.42.

The problem, according to both manager Ken Macha and Loaiza, is a lack of velocity. Loaiza has been consistently about five mph off on all his pitches. His fastball clocks in around 86 or 87 instead of in the low 90s, his cutter is down to around 82, and his changeup is 10 mph behind that.

"We need to get his velocity up a couple of clicks, and hopefully by pitching, that will happen," Macha said. "We could get him a couple of [side sessions] in the bullpen, but I don't think that will do any good."

Macha and pitching coach Curt Young theorize that Loaiza's appearances for Mexico in the World Baseball Classic this spring had a negative effect on him.

"You go down the list of the people that participated in this exhibition," Macha said, mentioning Bartolo Colon, Kelvim Escobar, Carlos Silva and Johan Santana. "None of those guys have gotten off to a good start, and they all participated in it."

Loaiza thinks there may be something to that theory.

"It could be that, starting too early," he said. "It could be pitching in the [Classic], then getting shut down the first few days when I got back to Spring Training. I didn't throw in a game for 10 days after I threw against Japan."

Neither Loaiza nor the A's coaching staff think there's anything wrong physically beyond a lack of arm strength.

"We've got video on everything, and it's pretty much the same delivery," Macha said. "Mechanically, he's been inspected to the ninth."

Loaiza said he feels fine. His workouts haven't changed, and the ball feels the same coming out of his hand. It's just the results that are different.

"I do worry, I do get frustrated because I want to do a good job," Loaiza said. "This time last year, and years ago, I'm throwing 91, 92 and right now I'm throwing 84, 85, 86. It's not me."

Explaining the lineup: Macha said Marco Scutaro, hitting .318 despite going 0-for-7 in the first two games against Texas, started at second base again on Sunday instead of Mark Ellis because he wanted to give Ellis, who is hitting .167, a few days off.

Macha has also been trying to give Milton Bradley a rest, with little success.

"I asked him how he was doing in the dugout yesterday, and he said, 'I'll make it through the next three hours,' " Macha said. "And [he] went and hit four rockets; 3-for-4 with a bullet at the shortstop. He's in."

Dan Johnson, meanwhile, is still out of the lineup while trying to find his batting stroke. He has one hit in 32 at-bats this year (.031), but Macha is staying patient.

"My contention is our best defense is with Dan Johnson playing first," Macha said. "There's no need to make a move just yet. When the Tigers come in he'll be out there playing first."

Bullpen update: Like Loaiza, closer Huston Street appeared in the Classic, and Macha thinks it affected his closer.

Street couldn't make it through one inning Friday, giving up a run on a pair of hits in a 6-3 loss, but bounced back Saturday to earn his third save on 16 pitches in a perfect ninth.

"I think the 25 pitches Street threw Friday night did him some good," Macha said. "He looked really sharp yesterday."

Macha has had no such worries about lefty reliever Joe Kennedy, who shuttled back and forth between the rotation and the bullpen last year, but, evidently, has settled successfully into his relief role this season.

Kennedy has allowed just one hit in 4 2/3 innings over six games, walking one and striking out three.

"He's been very pleasant, but not a surprise," Macha said. "I don't think he leaves anything out there when he's relieving. He comes in and he can hit 93. I'm pretty confident with him facing both right-handed and left-handed hitters."

Looking ahead: After taking Monday off, the A's welcome the Detroit Tigers, with Loaiza set to duel against RHP Justin Verlander (1-1, 6.52 ERA).

The A's swept the Tigers in the Coliseum last year, and have not lost a home series against Detroit since 1997.