St. Mark’s basketball star Erik Murphy of South Kingstown, in action in a game at Lawrence Academy last December, is currently ranked as the 21st-best prospect in the country by ESPN.com.

The Providence Journal / Kris Craig

SOUTH KINGSTOWN — One moment, Erik Murphy says it’s not a big deal. The next, he smiles, and you can see the excitement in his eyes.

Murphy, the South Kingstown resident who has committed to play for Billy Donovan at the University of Florida in the fall of 2009, is a strong candidate to become the first Rhode Islander chosen to play in the prestigious McDonald’s All-American basketball game next spring. The honor goes to the top 24 prospects in the country. Insiders say the selection process to be one of the lucky ones to follow in the sneakers of greats such as Magic Johnson, Michael Jordan and LeBron James can be highly political and at times even cutthroat.

Murphy, who will be a senior at St. Mark’s School in Southboro, Mass., this fall, says, “It would be an honor for me. I think it’s possible, hopefully.”

While he’d be thrilled with the prospect of such an accolade, Murphy downplays the significance of a spot on the team.

“Those things really don’t matter,” he says.

Maybe not, but the 6-foot-9, 215-pounder is certainly in position for all sorts of honors. He’s currently ranked the 21st-best prospect in the country by ESPN.com. Two other noted services, PrepStars and Scouthoops.com, rank him 26th. Another, Rivals.com, has him 69th, which only emphasizes the fickleness of rating 17- and 18-year-old prep stars.

“There’s no question he’s put himself in solid position to be considered,” said Jeff Goodman, a national recruiting writer for Fox Sports Scouthoops.com. “He’s one of the best players to come out of New England in a long time.”

Murphy’s quest for national accolades may ride on his play this week. He’s in Las Vegas to take part in one of the glamour national AAU team events, the Adidas Super 64. Murphy’s team, the New England Playaz, headed by former Boston Celtics assistant John Carroll, faces traditional power D.C. Assault this afternoon.

“This summer is crucial for him, and Vegas is when you establish yourself against the national people. He can really help himself,” said Goodman.

Murphy missed most of the key events last summer because of a knee injury, but that didn’t stop schools like Marquette, Boston College, Connecticut and Virginia from recruiting him.

Murphy ultimately chose Florida.

The timing of his decision has freed Murphy to concentrate on adding muscle to his frame and improving his skills. He says he’s gained strength working with Ritch Finnegan of South County Sports Performance and is shooting jumpers and practicing post moves with his father, former Boston College center Jay Murphy, several times a week.

“It’s a good feeling to know where he’s going already. Otherwise it would be a stressful summer,” said Jay Murphy, who played four seasons in the NBA and 10 more in Europe. “Now he’s just trying to get better. He knows that at Florida everyone is going to be a great player. He has to work even harder to get minutes.”

Erik Murphy’s summer got off to a great start earlier this month in Cincinnati, at the It Takes Five Classic. He scored 22 points in a win for the Playaz over the Atlanta Celtics and their big man, Derrick Favors.

Favors is the top big-man prospect in the country, according to most scouting services.

Murphy has plenty of competition at his Rhode Island workouts. At a light session last weekend, he and his father matched 25-footers in a H-O-R-S-E game. Erik’s 30-foot baseline bomb from just out of bounds proved to be the winning shot.

But his younger brother, 15-year-old Alex, is gaining recruiters’ attention, as well.

Alex, who earned Division III all-division honors as a freshman at The Prout School, is 6-7 and 180 pounds. He’ll join Erik at St. Mark’s in September and is also in Vegas this week, playing on a 15-and-under team coached by his father.

“Erik has worked so hard for this, and everything is coming true for him now,” said Alex Murphy. “I can’t wait to play with him this year. We haven’t done that since Broad Rock Middle School. If I can follow in his footsteps, I’d be really happy.”

Alex says Erik kids him, asking him when he’s going to commit to join him and Donovan in Gainesville. He’s already received some recruiting letters, and recently met with new Providence College coach Keno Davis on the PC campus.

“I’ve been to Florida and BC and a lot of schools with Erik but always been in his shadow. This time, I was the focus, which was really cool,” Alex said.

So who wins the father-son-brother basketball wars that inevitably break out? Everyone agrees that Alex can’t top Erik (“Not yet, but I’m in the game,” he says) and Jay is slipping a bit.

“He basically knows everything that there is to know and he doesn’t miss,” said Erik, “but he gets tired. He’s old.”

kmcnamar@projo.com