(SportsNetwork.com) - Seattle's Taijuan Walker tries to carry a tremendous spring into his first start of the season on Friday when the Mariners pay a visit to the Oakland Athletics for the start of a three-game series.

Walker earned a rotation spot with a nearly flawless effort in the Cactus League that saw him go 4-0 and pitch to a 0.67 ERA, while allowing 10 hits and five walks with 26 strikeouts in 27 innings.

The 22-year-old right-hander has pitched in 11 games in short stints with the Mariners over the past two seasons, going 3-3 with a 2.89 ERA.

"This is definitely what I've been working for all my years in the Minor Leagues and stuff," Walker said. "I've had ups and downs, but I feel comfortable and I feel good now."

Walker faced the A's twice in relief last year and allowed two earned runs in eight innings.

Seattle dropped two of three to the Los Angeles Angels of Anaheim to start the season, including a 5-3 setback in Wednesday's rubber match.

Hisashi Iwakuma (0-1), who had been 6-1 versus the Angels, struggled, as he gave up five runs -- four earned -- on nine hits and no walks in six innings, striking out three.

"He was up in the zone a lot over the first couple of innings," said Seattle manager Lloyd McClendon. "He just couldn't seem to get it down."

Oakland, meanwhile, split a four-game series with the Texas Rangers to start its campaign, but was rocked in Thursday's finale, 10-1.

Marcus Semien drove in the lone run for the Athletics, who were limited to six hits. Kendall Graveman (0-1) allowed eight runs -- seven earned -- on seven hits over 3 1/3 innings in his first major league start.

"I didn't make a lot of pitches, didn't locate well, and they made me pay for it," said Graveman, who had surrendered just one run in 25 1/3 innings this spring. "I gotta change speeds more, I gotta locate better and give my team a chance to win. I didn't do that today."

Hoping for a better effort on Friday the A's will give the ball to lefty Drew Pomeranz, who pitched to a 2.35 ERA in 20 games last season, including 10 starts. In those 10 starts, he was 4-3 with a 2.58 ERA and 1.13 WHIP

He also struck out 64 batters in 69 innings.

Seattle was 10-9 versus the A's last season.