Thomas Castellanos is an uber dual threat quarterback who has found his comfort zone inside the pocket.

That reflects the influence first-year head coach and quarterback czar Bill O’Brien’s has infused on the Eagles’ 5-11, 196-pound returning starter. Castellanos is trending away from being a runner who can throw and towards being the complete package under center.

Castellanos will be one of the seven signal callers on the roster who will compete in the annual Jay McGillis Memorial Maroon and Gold spring football game on Saturday (noon) at Alumni Stadium.

“I’m doing more of the stuff quarterbacks are supposed to do and I’m not running at all,” said Castellanos. “I’m in the pocket going through triple progressions and top-down reads.

“I’m doing what they are coaching me to do and polishing me up and getting me ready for the next level.”

Castellanos was a transfer from Central Florida who played in 13 games last season, with 12 starts, and emerged as one of the most dynamic run pass option quarterbacks in the Power-5.

Castellanos led BC in rushing with 1,113 yards on 215 carries and 13 touchdowns. He completed 189-of-330 passes for 2,248 yards and 15 touchdowns with 14 picks. His 3,361 yards of total offense are third most by a BC quarterback behind Matt Ryan and Doug Flutie.

While undergoing his positional transformation under O’Brien, offensive coordinator Will Lawing and quarterbacks coach John DiBiaso, Castellanos insists carrying the rock remains ingrained in his football DNA.

In BC’s 23-14 upset victory over No. 24 SMU in the Wasabi Fenway Bowl on Dec. 28, Castellanos rushed for 155 yards on 21 carries and two touchdowns. Most of those were designed runs on a day when the unsettled climate of early winter removed the passing game from the equation.

“I feel like when the pocket breaks down, I am always going to utilize my legs and extend the play and do the best that I can for the team, for sure,” said Castellanos. “But throwing the ball is wiser and we have a lot of good weapons and I try and utilize those guys.”

Some of those weapons are already established while others have emerged over the 15 practices that fill the spring schedule.

BC returns its top three wide receivers from last season – Lewis Bond (52-646-7), Joe Griffin (25-345-1) and Dino Tomlin (24-312-0). The tight end position was under represented in the BC offense last season, but junior Jeremiah Franklin’s sample-sized contributions suggests untapped potential that Castellanos is ready to explore. Castellanos also feels tailbacks Kye Robichaux and Alex Broome will emerge as three-down ballcarriers who can be instrumental in the passing game.

“Last year he (Franklin) showed some glimpses of what he can be with some amazing catches and some wild plays,” said Castellanos. “Hopefully this year I can target him more and he can continue to make those plays for me. He has good hand-eye coordination so whenever it comes to him, it’s like a magnet and he just catches it.”

O’Brien intends to run the spring game more as a scrimmage with an attitude as opposed to a straight up match. There will be no gimmick scoring format and the only numbers on the scoreboard that matter will be the time clock.

O’Brien wants to use the spring game as a test case for the coaching staff and a fun event for the players that can serve as a blueprint for when the team returns in August for training camp.

“I will say it will be a great day and a very competitive practice,” said O’Brien. “In terms of a game, I would say it will be more like the scrimmages that we’ve run on Saturdays, which have been very competitive.

“We are going to have everybody out here to have some fun, crank the music and get the fans involved and these guys will battle hard so it will be a good day. This is one of the most important tools we have to evaluate these guys.”