BOSTON -- Through much of his time at Texas A&M, Kyle Martin couldn't make up his mind when it came to his delivery. He would go sidearm. Then he'd go over the top. Then he'd switch it up again. Part of the indecisiveness had to do with moving back and forth between starting and relief.

Once the Red Sox selected Martin in the ninth round of the 2013 Draft, the waffling stopped.

"Once I got drafted by Boston, I got a call from Ralph Treuel," Martin said. "He was the [Minor League pitching] coordinator for the Red Sox. And he said, 'Hey, we drafted you as an over-the-top guy. You're going to start as a reliever, and we'll see what happens from there.' I just haven't looked back from there."

Martin has fed off of that plan to the point where he is one of Boston's best relief prospects, and he could be close to a call to the Major Leagues.

The 25-year-old -- ranked No. 22 among Red Sox prospects by MLBPipeline.com -- spent time earlier this month at MLB's Rookie Career Development Program in Virginia. This week, he is at the Red Sox's Rookie Development Program at Boston College.

Programs such as those are aimed for players believed to be in the home stretch of their development.

"Kyle has continued to improve as he's climbed to higher levels," Red Sox vice president of player development Ben Crockett said. "He's made adjustments to his pitches and pitch usage, and remains aggressive to the strike zone. He embraced an arm-slot adjustment coming into professional baseball, worked very hard and has kept getting better."

For Martin, the over-the-top delivery is actually a three-quarters release. The result is a 95-mph fastball that generates a lot of ground balls.

"I feel like I've slowly worked on it and gotten more comfortable with it," Martin said. "Now that I've found that high three-quarters slot, it's really been where my comfort level is."

Martin's second pitch is a changeup that is turning into a real weapon.

"I love my changeup," Martin said. "It's kind of my feel-good pitch. If I'm a little off one way or the other, I use the changeup to hone back in to where my arm slot needs to be, and it helps my direction and staying in my lane."

Martin spent all of 2016 at Triple-A Pawtucket, notching a 3.38 ERA with 78 strikeouts over 66 2/3 innings. He held opponents to a .239 average.

After going to Spring Training as a non-roster invitee last year, Martin is now on the 40-man roster, as the Red Sox made sure to protect him prior to the Rule 5 Draft.

Martin will be looking to round out his development in the coming weeks.

"I think continuing to learn the game, continuing to talk with everyone I can and soak up as much knowledge as I can is key, because it is a big step from Triple-A to the big leagues," Martin said.

Entering his second Major League Spring Training, Martin is enthused to pick up more tips from closer Craig Kimbrel and some of the other veteran relievers.

"Keep working on a routine, that's what I took from last year," Martin said. "All those guys in the bullpen in Boston, when I was there in Spring Training, I just sat there and listened. Craig Kimbrel had his own routine. Junichi Tazawa had his own routine. Everyone had their own routine. Robbie Ross Jr. [Jr.] had his own routine. Just kind of take bits and pieces from each one, and whatever works for me, go from there."

Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and **Facebook**.