The rotation, however, is making an even greater impact.Erasmo Ramirez looks to give the Mariners another dazzling performance on the mound Sunday, when they attempt to conclude this rain-shortened three-game set with a second straight win over the Oakland Athletics.Seattle (4-1) made a major splash in free agency, signing Cano to a 10-year, $240 million contract and he's been effective so far. The five-time All-Star second baseman is 8 for 19 (.421) with two RBIs in five games while also drawing five walks.Cano got two more hits with a walk Saturday, but Felix Hernandez had eight strikeouts and finished two outs shy of a complete game in a 3-1 win at Oakland (2-3).While Cano has his Mariners stint off to a strong start, Hernandez and the rest of the rotation have been superb.Seattle's starting pitchers have compiled a 1.62 ERA with 37 strikeouts in 33 1/3 innings, limiting opponents to a .169 batting average. They've been particularly impressive over the past three games, giving up two runs and eight hits while fanning 20 in 20 1/3 innings.The only thing that's stopped the Mariners' rotation has been the weather, with rain postponing Friday's contest.Now, Ramirez looks to keep Seattle surging as he gets a second turn in the rotation in place of All-Star right-hander Hisashi Iwakuma, who is on the disabled list recovering from a torn ligament in his right middle finger.Ramirez was impressive Tuesday, yielding two runs with six strikeouts in seven innings of an 8-3 victory at the Los Angeles Angels. He was 6-6 with a 4.25 ERA in 21 starts over his first two seasons, but he went 3-0 with a 1.14 ERA in six games -- five starts -- during preseason."I'll just pitch the same, use all my pitches, try to get first-pitch strikes, try to get strikeouts or ground balls," Ramirez told the team's official website. "That's always my goal: just attack, attack, attack. It was working in spring, so why change?"Ramirez is 0-2 with a 3.78 ERA and 21 strikeouts in 16 2/3 innings over four games -- three starts -- versus Oakland.Cano has been much more successful against the A's, particularly at O.co Coliseum. He owns a .365 average with five homers, 10 RBIs and 11 runs over his last 15 games there, going 11 for 27 (.407) over the past six.Oakland has rotated wins and losses through its first five games, and it would like to maintain that trend to create some momentum heading into a nine-game road trip.The A's will send Sonny Gray to the mound, and he's tossed 13 straight scoreless innings, dating to last year.The right-hander kept that stretch going with six shutout innings and seven strikeouts in Monday's season opener. He didn't get any help from his teammates, who mustered five hits -- four singles -- while closer Jim Johnson surrendered two runs in the ninth of in a 2-0 loss to Cleveland.Gray went 1-0 in two starts against Seattle as a rookie last year, yielding two runs with 15 strikeouts in 12 innings.Brandon Moss is putting together a strong stretch at the plate, going 6 for 13 with two RBIs over the past four games. The first baseman is 10 for 26 (.385) with three homers and four RBIs over his past eight home meetings with Seattle.