LAKEWOOD, N.J. - Jarred Cosart already has the big-league arm.

"He's had two games where I thought I could have taken him into a big-league game and he'd have been real competitive even at 19," said Mark Parent, the first-year manager of the Phillies' single-A Lakewood club. "Not to say he's ready. But in those games he had enough command and enough zip, and his off-speed stuff was good."

Parent, a former catcher who spent 13 seasons in the majors, including his final two with the Phillies, knows that it takes a lot more than a big-league arm to get to the big leagues, and that's what he hopes Cosart learns in his first full professional season.

Cosart, a 38th-round draft pick in 2008, is eager to learn and happy to finally be doing it in front of fans at Lakewood's spiffy FirstEnergy Park. After signing just before the August deadline in 2008, Cosart pitched in the Florida Instructional League later that year, then made seven starts in the Gulf Coast League in 2009.

"That's the lowest of the low," he said. "It's hot, it's all noon games and there are five people watching you. Having a crowd around you is real baseball. This isn't the big leagues - it's 8,000 people - but the seats are filled. Seeing the fans gets you excited. I like to put on a show and people want to see a hard fastball and home runs. I try to limit the home runs."

So far this season, Cosart has put on some pretty good shows. In eight official starts for the single-A BlueClaws, he is 5-1 with a 3.12 ERA. He has struck out 52 batters and walked eight, and allowed only 29 hits in 401/3 innings. Those numbers don't include his ninth start, which he made Thursday against Hagerstown. Cosart was knocked out with one out in the fourth inning after surrendering five runs and six hits. The game, however, was suspended and the stats will not become official until it is completed.

Statistics are not the most important thing for Cosart as he hones his big-league potential. One of Cosart's less attractive labels is that he lacked maturity coming out of Clear Creek High School in suburban Houston.

"There was kind of a knock on that when I signed," Cosart said Wednesday, the morning after his 20th birthday. "I think I've definitely come a long way."

Cosart said he has no idea why he received that label.

"Honestly, I've never been able to figure that one out," he said. "Maybe it was in my scouting report. There is always going to be somebody out there who says I can't do something. I'm always looking to improve and prove some people wrong."

Parent, on the contrary, believes Cosart can become a big-league star if he goes about his business in the proper way.

"He has a ways to go," the Lakewood manager said. "From what I've heard about him in the past, he's really immature, but when I see him around these guys in a day-in-and-day-out setting where he's competing for a job and competing for a livelihood, he's starting to understand that it's more than just coming out and being me. It's about a team-type thing."

Cosart is considered the top pitching prospect at Lakewood, even though as a 38th-round pick he is the lowest draft selection on the BlueClaws' roster. That low selection is an anomaly; most teams bypassed him because they thought he was going to the University of Missouri as a pitcher and outfielder. The Phillies took a chance with a late-round pick, continued to scout him after his high school season, and offered him a $550,000 signing bonus. He accepted 42 minutes before the signing deadline.

"Money was not the issue because I really had no problem going to college," he said. "The way the Phillies showed an interest in me, I decided I wanted to play professional baseball. They believed in my ability."

And now, after watching him through the first two months at Lakewood, they believe in it even more.

"He's the best young arm I've seen in a long time," Parent said. "If you look at his body, he's only going to get bigger and stronger. And when the maturity thing kicks in . . . it's going to be a good thing for the Philadelphia Phillies. It's just a matter of time. It's not my call, but I could see him a year from now jump a level."

It will be assistant general manager Chuck LaMar's call on whether to jump Cosart, but he's not even considering it right now.

"I never put any kind of timetable on anybody," LaMar said. "He's done a fine job in his first year truly in professional baseball. His stuff is obvious. He has an outstanding fastball and a breaking ball and change-up that will continue to improve. If he continues to stay healthy and do what he's doing, he has a chance to progress quickly."