Kansas City (39-50) at Tampa Bay (55-32)

Matt Garza was supposed to be just one of the pieces that would help improve a Tampa Bay Rays pitching staff that last season was the worst in baseball.

Instead, he might be putting them over the top.

Fresh off two dominant outings, Garza will look to lead the major league-best Rays to their eighth straight win on Monday as they try to complete a four-game sweep of the visiting Kansas City Royals.

Tampa Bay’s pitching staff had a major league-worst 5.53 ERA last season, but holdovers Scott Kazmir, James Shields and Andy Sonnanstine have combined for 24 wins while giving the Rays (55-32) three quality starters.

The plan was that Garza (7-4, 3.47 ERA) would give them a fourth, but through 11 starts he was just average, going 4-3 with a 4.38 ERA.

Recently, however, Garza has looked like the potential ace Tampa Bay thought it was getting when it acquired him from Minnesota in the offseason. The 24-year-old tossed his first career complete game in a 6-1 victory on June 26 at Florida, allowing just a solo homer while striking out 10, and followed that up by allowing five hits and an unearned run in a 3-1 win over the defending champion Red Sox on Tuesday.

“I was just trying to stay pitch-to-pitch,” Garza told the Rays’ official Web site. “Don’t try to do too much or be too fancy. I just go out there and do the best I can for as long as I can.”

Garza has been practically untouchable over his last six starts at Tropicana Field, going 5-1 with a 1.28 ERA.

As Garza has improved, Tampa Bay’s pitching staff has turned into one of baseball’s best. The Rays’ 3.57 ERA is the third-best in the majors, representing a near two-run improvement over last season.

Shields matched Garza by picking up his seventh win on Sunday, allowing two runs while striking out eight over seven innings in Tampa Bay’s 9-2 win over Kansas City (39-50).

The Rays have scored a major league-best 82 runs since June 24 as they’ve won 11 of their last 12 games. Rookie Evan Longoria, a candidate for the final AL All-Star spot, is hitting .423 with four homers and 15 RBIs during that stretch.

“Right now he’s playing with a lot of confidence,” manager Joe Maddon said. “It’s really not a surprise. This is what he’s capable of doing. … I think you’re going to see this kind of performance for many years to come.”

The Royals won 11 of 12 from June 14-27 to climb within six games of .500, but have since dropped seven of nine. They’ve scored only four runs so far in three games at Tampa Bay, and with a loss Monday would suffer their third four-game sweep this season.

Kansas City will turn to Gil Meche (6-9, 4.74) to try to end its skid, and Meche has been pitching better recently after a 3-8 start.

He was 3-0 with a 2.08 ERA in his last four starts in June, but wasn’t happy after his last outing. Meche gave up five runs - four earned - over six innings in a 5-2 loss at Baltimore on Wednesday.

“I was horrible. I struggled,” Meche said. “One of those days when you’re not pitching good. Just a bad outing.”

Meche is 1-4 with a 5.65 ERA in eight career starts against Tampa Bay.

He’ll have his hands full with the Rays’ lineup, particularly Carlos Pena. Tampa Bay’s first baseman is 5-for-12 with a homer and seven RBIs in the first three games of this series, and is a .421 (8-for-19) lifetime hitter against Meche with three homers.