As a rookie in 2002, Carlos Zambrano was a promising pitcher for the Chicago Cubs who showed flashes of being a star but had one major flaw: He walked too many batters.

The soon-to-be Cubs' ace found his way, improving over the next three seasons, but now appears unable to shake recurring control problems.

Zambrano went 4-8 in 32 games in 2002, including 16 starts, while walking more than five batters per nine in-nings. He also allowed nearly eight hits an inning for a WHIP (walks plus hits, divided by innings pitched) of 1.45.

In 2003, the Cubs' right-hander found his control - lowering his walks per nine innings from 5.23 to 3.95 and finishing the season at 13-11 with a WHIP of 1.32. His earned run average dropped half a run fro m 3.66 to 3.11 even though he gave up about the same number of hits per nine innings as the year before.

By the end of the 2004 season, Zambrano had become one of the most dominant pitchers in the National League. His walks per nine innings were down to 3.48 and his strikeouts per nine innings crept over eight. Batters hit just .225 off him, and his ERA dropped to 2.75 as he went 16-8.

Zambrano's string of stellar seasons continued in 2005, when he went 14-6 with an ERA of 3.26 and a WHIP of 1.15. His walks and strike outs per nine innings stayed constant, and batters hit just .212 off of him.

The 2005 campaign was also the third straight season Zambrano tossed 200-plus innings. One negative over that three-year stretch was an increase in home runs allowed. In 2003, Zambrano gave up just nine long balls in 214 innings. He surrendered 14 HRs in 209.2 innings in 2004, and saw that total jump to 21 in 223.1 innings the follow-ing year.

Many speculated that the stretch of 200-plus-inning seasons and pitching in the World Baseball Classic prior to the 2006 season caught up with Zambrano as he struggled with his control. He ended up dishing out 4.8 free passes per nine innings and allowed 20 home runs.

Concerns were more or less pushed aside, however, as Zambrano finished with a record of 16-7, an ERA of 3.41. He was still pretty tough on hitters, with a batting average against of just .208, a WHIP of 1.29 and nearly a strike out an inning.

It's now 2007, and Zambrano is looking more and more like that wild 21-year-old with a rocket arm than a wily veteran who's mastered the strike zone. Through three starts, he's walked 11 batters in 16 innings and allowed four home runs.

While some might point to his antics on and off the mound as a problem, I just do see it that way. Neither does Cubs manager Lou Piniella from reading his comments about the excitable flame thrower.

Piniella has preached throwing strike one, and went to the mound early this season to remind closer Ryan Dempster about it.

Perhaps it is time for "Uncle Lou" to have a sit down with his No. 1 starter about the importance of not walking guys.

A pitcher with the stuff Zambrano has should be able to go after just about anyone in the league. He doesn't need to try and strike out every batter to be successful.

If he continues to walk guys at this pace, his pitch counts won't allow him to be the workhorse the Cubs need, and the bullpen will start to suffer. Also, given the team's history of arm problems, it probably won't be long before Zambrano comes up lame.

Maybe he's already having problems and has remained silent about it. I sure hope that isn't the case. The Cubs could ill afford to lose yet another once-promising pitcher.

Joel Fellers is the sports editor for pantagraph.com. He can be contacted at jfellers@pantagraph.com