Lester set for A's debut in matchup with Royals

( - Newly acquired ace Jon Lester will make his first start in an Oakland uniform on Saturday when the Athletics clash with the Kansas City Royals in the second contest of a three-game series at Coliseum.

Lester, the ace of last year's World Championship Red Sox, was dealt in a massive day of trading by Boston on Thursday. The A's acquired the left-hander along with outfielder Johnny Gomes in exchange for slugger Yoenis Cespedes.

Although his former team is having a difficult year, Lester is enjoying the best of his entire career. He went 10-7 with a 2.52 ERA in 21 starts for Boston, a team he had pitched with for eight and a half seasons. While his record may not be overly impressive, his ERA is on pace to top his previous career best by more than half a run. He has also struck out 149 batters in 143 innings, giving him his highest strikeout per nine innings rate (9.4) since 2010.

The 30-year-old veteran was scheduled to pitch on Wednesday for Boston, but he was scratched from the outing. The day off means that Lester will be plenty rested for this contest, as he has not been on the mound since July 25 when he allowed two runs over six innings of work against the Rays.

In the start before that one Lester made his one and only appearance against the Royals this season. In a masterful effort he finished with eight shutout innings and eight strikeouts to pick up his 10th win of the campaign. He is 7-3 with a minuscule 1.43 ERA in 11 career starts against Kansas City.

There will be much less fanfare surrounding Kansas City starter Jason Vargas, although he will be bringing a needed boost to the Royals rotation.

The veteran left-hander has been out since July 8 as he dealt with an appendectomy. Getting his arm back in the mix will be big for Kansas City, as Vargas has pitched to an 8-4 record and 3.31 ERA in his first season with the club.

In that last start on July 8 he allowed two runs over a laborious 5 2/3 innings in which he gave up six hits and a pair of walks while throwing 109 pitchers. He was tagged with the loss in the contest.

Vargas is 6-6 with a 3.28 in 18 career appearances against Oakland, although he has not yet faced them as a member of the Royals.

Lester and Vargas will have to pitch extremely well to live up to the pitching duel between the Royals and A's on Friday. Raul Ibanez's home run in the fifth inning accounted for the only run in a 1-0 victory for the Royals.

Jeremy Guthrie threw six shutout innings to earn the win and Greg Holland closed the door in the ninth for his 30th save. Holland has now recorded 30 saves in back-to-back seasons.

Sonny Gray took the loss despite pitching seven stellar innings in which he let up just one run on three hits and struck out seven. Josh Reddick went 3- for-4 with a double for the A's, who had only five hits as a team.

The Royals have won three straight games, while the A's have lost three of their last four.

Oakland won five of six from the Royals a year ago.