Four weeks into the 2013 season, most if not all Japanese and JA major leaguers are playing well. I’d only classify Chicago Cubs second baseman Darwin Barney (.208 average, 10 hits in 48 at-bats) and Blue Jays infielder Munenori Kawasaki (.220 average, three RBI in 17 games) as struggling at the plate.

Yet Barney, who has a perfect fielding percentage, is a clear defensive specialist, and Kawasaki is a minor leaguer filling in (for injured star Jose Reyes) because Toronto can’t afford anyone else. So I don’t expect to see any immediate improvement from either anytime soon.

Locally, Hiroyuki Nakajima will soon report to Triple-A Sacramento River Cats for a rehab assignment. He’s been in extended spring training since straining his hamstring in March. I expect him to be a backup shortstop once he’s called up. He’s getting paid to play in Oakland, so we’ll see him in an Athletics uniform well before the All-Star break.

River Cats lefty Hideki Okajima (0-1) has 15 strikeouts in 13.2 innings through 11 appearances, issuing just two walks. Like Nakajima, I’d be surprised if he isn’t with the A’s by July.

There is good news to report on Giants second baseman Kensuke Tanaka, who is tearing it up in Triple-A Fresno. Tanaka, who struggled mightily this spring, now has a .434 on-base percentage, a .398 batting average, six doubles, one triple, 12 RBIs, 21 runs scored and five steals for the Grizzlies. He’s also adjusted quickly to handling a sleeker baseball, which has improved his fielding. It looks like we may actually get to see “Tanaka-time” in San Francisco this season.

Here’s the line of the month for the rest of the pitchers and position players around the league.

Texas Rangers ace Yu Darvish (5-1) has a 2.33 ERA with 58 strikeouts in 38.2 innings while his teammate Yoshinori Tateyama (1-0) has a 3.60 ERA in five relief appearances.

Seattle Mariners right-hander Hisashi Iwakuma (2-1) has a 1.67 ERA with 37 strikeouts in 37.2 innings.

Los Angeles Dodgers closer Brandon League has appeared in 11 games, converting 8-of-9 opportunities while issuing just one walk. Angels long-man Jerome Williams (1-0) has a 1.69 ERA in eight appearances with a 1.03 WHIP.
Kansas City Royals starter Jeremy Guthrie (3-0) has posted a 3.06 ERA in five starts with 24 strikeouts.

New York Yankees pitcher Hiroki Kuroda (4-1) has a 2.25 ERA in five starts including a complete game.

Boston Red Sox relievers Koji Uehara and Junichi Tazawa continue to impress. Uehara has a 1.69 ERA in 10.2 innings with 12 strikeouts, and a 0.75 WHIP. Tazawa (2-1) has 14 strikeouts in 12.2 innings with a 2.84 ERA. Outfielder Shane Victorino has a .292 batting average with 21 hits, eight RBIs, and a. 358 OBP.

Milwaukee Brewers lead-off hitter Norichika Aoki has a .339 on-base percentage, three homeruns, six RBIs, and is 4-of-6 on stolen bases.

Yankees outfielder Ichiro Suzuki emerged from his slump, and is now hitting .268 with one homerun, and five RBIs.

Washington Nationals catcher Kurt Suzuki is batting .241 with two homeruns, and seven RBIs. He also has a .993 fielding percentage.

Drew Morita, a Yonsei from the island of Kaua‘i, grew up rooting for the Oakland A’s but is now a loyal San Francisco Giants fan. He writes from San Francisco. Follow him @drewmorita or e-mail him at drew_morita@yahoo.com.