'HAWKS GARTHWAITE UP TO THE CHALLENGE UTILITYMAN RESPONDS TO MANAGER'S PLEA FOR OFFENSE.

Byline: Gideon Rubin Special to the Daily News

LANCASTER - JetHawks manager Bill Plummer told utilityman Jay Garthwaite in a late-July meeting he needed to start producing.

With the team's three most productive hitters - Miguel Montero, Chris Carter and Stephen Drew - promoted to higher levels, Plummer said Garthwaite needed to drive in runs as he had in previous stints at Lancaster, as much for his own sake as the team's.

Garthwaite has responded, batting .367 (33 for 90) with eight homers and 32 RBI in August, easily his best month. He has 39 RBI in his past 26 games.

``Pretty scary, aren't they?'' Plummer said of Garthwaite's numbers the past four weeks.

Garthwaite, in his fourth year at Lancaster, has been inconsistent, batting .351 in April and .329 in June but .236 in May and .213 in July.

The timing of his recent surge couldn't have come at a better time for the JetHawks. Along with Jeff Cook, who batted .542 (32 for 59) during a 13-game hitting streak that ended last week, Garthwaite's bat helped lead the JetHawks to their best stretch of the season. Lancaster won eight consecutive games and 10 of 11 games from Aug. 5 to 16, helping them close in on a playoff berth.

With 13 regular-season games remaining, Garthwaite (.297, 16 HRs, 89 RBI heading into Tuesday night's game at Bakersfield) could become the eighth player in franchise history to drive in 100 runs in a season.

Cook (.325, 18 HRs, 84 RBI) also has a chance to drive in 100.

``I told him the last month when those guys left (for promotions), you've got to get 40 or 50 RBI,'' Plummer said of Garthwaite. ``I told him you're capable of doing it and we need it, too.''

Said Garthwaite: ``I'm just trying to drive the ball. I'm trying to concentrate more on getting people in, that's how I've been helping the team.''

--Swing doctor: Hitting coach Damon Mashore has worked three years with Garthwaite - two in Lancaster and one at Double-A El Paso (Texas) - on harnessing a powerful swing that has a tendency to get too long.

Mashore said it's been difficult to get Garthwaite to buy into the adjustment after having success in the lower levels of the minor leagues and a prolific career at the University of Washington. He hit 16 homers with a .603 slugging percentage in 60 games as a junior for the Huskies.

``It's hard to argue with success sometimes,'' Mashore said.

It became apparent Garthwaite's swing needed an overhaul last season, when he struggled against more advanced Double-A pitching, batting .189 (23 for 122) with two homers before finishing strong in the second half at Lancaster.

Mashore said he's been trying to get Garthwaite to keep his weight back and take a more direct downward path to the ball. Mashore and the parent Arizona Diamondbacks believe Garthwaite can improve his power and reduce his strikeouts with a shorter swing that produces more backspin.

Mashore believes the adjustments will enable Garthwaite to have success with a better chance of carrying over to a higher level.

``He's worked hard all year at it, and it's just starting to click now,'' Mashore said.

--Road woes: The JetHawks opened a three-game series against Bakersfield on Tuesday at Sam Lynn Ballpark, where Lancaster has lost 19 of 24 games. The JetHawks are 3-6 against Bakersfield this season.

Gideon Rubin, [phone]

gideon.rubin(at)dailynews.com