The 6-foot-1, 175-pound Brennan went 5-2 last spring for the Highlanders, striking out 83 batters in 43.1 innings and recording a 3.22 ERA; his fastball has touched as fast as 87 to 88 miles per hour. At the plate, he batted .345 with 17 RBI.
"I want to play and I want to win, and I think Franklin Pierce will give me a great opportunity to do both," Brennan told ESPNBoston.com.
Brennan also stars for the Highlanders' football team, where he is one of the region's top returning quarterbacks. Last season, he completed 59 percent of his passes for 1,835 yards and 22 touchdowns as the Highlanders made the MIAA Division 2 Central playoffs.