PORT CHARLOTTE, Fla. — John Mayberry Jr. is creating a name for himself in his first spring training with the Philadelphia Phillies.

Mayberry, the son of former Kansas City Royals first baseman John Mayberry, has gone from possible Triple-A project to a player on the cusp of landing a spot on the Opening Day roster in the first three weeks of camp. The younger Mayberry, 25, was back in the lineup when the Phillies visited the Tampa Bay Rays on Thursday.

Mayberry entered the day hitting .290 in 10 games. No Phillies player has played in as many games or has racked up as many at-bats.

"I'm obviously very pleased to be given the chance to go out there and play pretty much every day, and to play to the best of my ability," Mayberry said.

Mayberry has made the most of the playing time by showing off the power stroke that made the Texas Rangers use the 19th overall pick in him in the 2005 amateur draft. Mayberry has nearly matched reigning National League home run-champ Ryan Howard in run production.

While Howard leads all big leaguers with four home runs this spring, Mayberry is right on his heels with three. Both hulking sluggers — Howard is 6-foot-5, 235 pounds, Mayberry is 6-foot-6, 230 pounds — have 10 RBIs apiece.

"He's got a lot of potential and a real good chance to be a really good player," Phillies manager Charlie Manuel said of Mayberry. "I think sometimes it takes you a while to get it, it takes you a while to get used to pro ball... he's right at the (age) where it's a good time for him to take off as far as higher baseball. With the talent he's got, there's no reason he can't play in the big leagues."

Mayberry, acquired in a swap of first round picks in December with Texas for outfielder Greg Golson, hit .264 with 20 home runs between Double-A and Triple-A last season in the Rangers' system. In 2007, he hit 30 home runs between Single-A and Double-A.

But Mayberry never played a game with the Texas Rangers. He's hoping to follow the same path that led his dad to big-league fame.

The elder John Mayberry, drafted by the Houston Astros in 1967, didn't become a major league regular until 1971, when he hit .298 with 25 home runs and 100 RBIs in his first season with the Royals. Mayberry went on to hit 255 home runs over a 15-year career.

"My dad has mentioned time and time again that there are a lot of teams out there that if things don't work with one team, as the case was with his career, they might work out with another," the younger Mayberry said. "He was traded to Royals, got off on the right foot and ended up having a 15-year career. So if you look at it from that perspective, it's easy to be positive."

Mayberry still may have an uphill climb to making the Phillies' 25-man roster when camp breaks next month.

With Geoff Jenkins, Matt Stairs, Eric Bruntlett and Greg Dobbs, the bench is nearly set in stone. The Phillies also have veterans Marcus Giles and Miguel Cairo in camp.

Mayberry, however, can continue helping his cause by maintaining a power pace with Howard over the next three weeks.

"I'm just letting them play," Manuel said of evaluating possible bench players. "We haven't even started talking about that yet. We're just putting them out there and letting them play."