But he's no swimmer.
"From five years old, I was all baseball," Delmonte said of avoiding the pervasive swim-club scene in Cherry Hill.
Still, Delmonte used to have this issue with his left arm. He's a left-handed ace who could hardly pitch last season because of soreness and looseness in his left shoulder.
Delmonte joined the Cherry Hill West swimming team this past winter. Never mind that he had zero experience in the pool, didn't really know a butterfly from a breaststroke, and was pretty slow at his best event - at least at first and certainly by the standards of the Lions' powerful program.
"What was great was getting to be friends with a lot of those guys," Delmonte said of his first and only season on the team. "It was a whole new world."
Delmonte is believed to be the first Cherry Hill West student-athlete to be accepted to the Naval Academy to play sports, according to Lions baseball coach Dan McMaster.
McMaster said Delmonte's decision to join the swim team - and to dive all the way in, as it were - underscores his team leader's dedicated, detailed approach.
"Take away the academics and the athletics, the big thing about Brenden going to the Naval Academy is that it says something about his character," McMaster said. "It shows what kind of young man he is."
Delmonte is one of seven Cherry Hill West seniors who have been starting since their sophomore seasons. They are the nucleus of a program that has made gradual progress over the last two years and could burst into prominence this season.
One big key for the Lions is Delmonte's health. With changes in the bats this season expected to create lower-scoring games, pitching will be more important than ever in high school baseball, and Delmonte has the stuff and demeanor to be dominant on the mound.
"Our guys feel like when Brenden's on the mound, they can compete with anybody," McMaster said.
Delmonte last season pitched just 20 innings, all of them in late May. He struck out 27. In addition, Delmonte, also a rightfielder, batted .410, was an Olympic Conference Patriot Division first-team selection, and was chosen as a member of the Olympic-Colonial team for the Carpenter Cup.
Delmonte said his shoulder is "100 percent better" this season, thanks to rest and those laps in the pool.
"Last season was an eye opener," Delmonte said. "It was scary because you don't know if you're going to be able to pitch again. I was lucky I was able to come back late in the year."
Delmonte thinks the Lions can challenge defending champion Shawnee for the Olympic Patriot title, and also make a run through a deep, crowded field in the South Jersey Group 4 tournament.
"We've got a lot of seniors who have through a lot together," Delmonte said. "We feel like this is our year."
The Lions' hopes of jumping into the conversation about the best teams in South Jersey could rest on the strengthened left shoulder of their pitching ace.
Delmonte said he swam 3,000 yards a day with his new team during the winter. He cut his best time in the 50-yard freestyle from 32 seconds at the beginning of the season to 26 seconds at the end.
Mostly, the Navy-bound athlete got ready to do his best work on dry land by diving in the water.
"Every weekend, I would throw after swimming all week," Delmonte said. "I could feel my shoulder getting stronger and stronger. I'm ready to throw better than I ever have."
Contact Phil Anastasia at 856-779-3223, email@example.com, or @PhilAnastasia on Twitter. Read his blog, "Jersey Side Sports," at www.philly.com/jerseysidesports