The Colorado Rockies recently invited former Marshall pitcher Mike Mason to participate in their fall instructional program, and Mason reported for duty in Scottsdale, Ariz., on Sept. 24.

The Fall Instructional League is a month-long offseason program typically comprised of lower-level minor leaguers. An organization's top coaches and player development personnel focus on developing young players and provide them with opportunities to refine their skills in practices and games.

"It's a way to see where you're stacking up against a lot of players," said Mason, one of eight Marshall players drafted in the past two years. "It feels good to get invited out here, so hopefully I'll have a good month and then start training in the offseason."

Mason was selected by Colorado in the 24th round of the 2012 draft. The Rockies assigned the 22-year-old left-hander to their rookie league affiliate in Grand Junction, Colo., and he made his professional debut, a successful relief appearance, on June 22.

"It was good to get my feet wet in the organization," said Mason, who compiled a 4.15 ERA in 801/3 innings with the Thundering Herd last spring.

A starting pitcher at Marshall, where he finished his four-year career ranked fourth on the school's all-time strikeouts list, Mason immediately experienced the ups and downs associated with playing professional baseball and accepting a new role in the bullpen.

He fired two scoreless innings and recorded a win in his professional debut, but didn't fare as well in subsequent outings.

Four days after his debut, Mason surrendered five runs and was removed from a game against the Orem Owlz before recording an out. He allowed two more runs in 11/3 innings in his third career appearance on June 30.

Mason said he never doubted his abilities. Instead, he remained confident and worked hard - characteristics Marshall coach Jeff Waggoner said might help him accomplish his lifelong goal of playing in the major leagues.

"He's always been a hard-working kid in our program," Waggoner said. "It's a lot more than just baseball. He was a leader, a good student. He always did what you asked him to do, and he believed in himself.

"He's got the ability, and I don't see him stopping," Waggoner said. "He'll continue to work hard and keep getting better and better."

In his final 12 appearances of the season, Mason struck out 21 in 20 innings, allowing just five runs. Overall, he finished with a 3-0 record, 5.52 ERA and 29 punchouts in 291/3 innings, including three postseason innings.

"The first month it took a little getting used to, but I got pretty good at it," Mason said of throwing in relief. "Toward the end of the season I was pitching more and my arm was reacting well. I felt pretty strong."

The 6-foot-3, 190-pound hurler pitched effectively in two appearances in the Pioneer League Playoffs, retiring nine of 11 batters he faced and striking out five.

Although Grand Junction lost the hotly contested opening round-series, falling victim to the Ogden Raptors in three games, Mason flourished in pressure situations. He stranded a couple of inherited runners in Game 2 of the series, paving the way for a come-from-behind Grand Junction win, the franchise's first playoff victory.

Ed Santa, the Rockies scout who signed Mason, said the organization is pleased with Mason's progress.

"He's a left-handed pitcher who can throw the ball up to 92. 93 miles per hour, and he always throws strikes," Santa said. "With his potential, we think that he's a major league prospect."

Santa said Mason's willingness to succeed could eventually land him in the major leagues.

"When you get to the minor leagues, all of the guys are good," the veteran scout said. "What separates the guys is their makeup and their ultimate competitiveness and desire to be in the big leagues and be a successful pitcher.

"Mike's going to be a kid who will do whatever we tell him to do to get to the major leagues."