The young pitcher has posted solid numbers through the first six weeks of the season with a 2-2 record and a 3.97 ERA and a .241 opponents average. Those competitive numbers, including four quality starts, are largely the result of increased command of his fastball.
"The fastball's my number one pitch and being able to command it. My slider comes next and my changeup is next," said Mathieson.
Another key to the young right-hander's success is the same as any young pitcher, simply to stay healthy. Although at 22 years old, he could suffer a setback and still have a respectable Major League career, it is not something he plans on.
"The biggest thing for me is just staying healthy, being able to go out there every fifth day and pitch," said the young righty.
One of the ways to be effective is to learn the nuances of situational pitching, and that is one of the things he has learned from pitching coach Tom Filer. Filer isn't one for talking about himself, but his pitchers performance and their statements speak for themselves.
"Filer's been great. We talk about situational pitching everyday. He picked up where we left off with my other pitching coach. He's made me much more of a pitcher than a thrower," said Mathieson.
But that's not the only advantage he has gained from his elder statesman of a pitching coach.
"I throw two bullpens a week between starts and the big thing is to go out there with a purpose, something to work on. Every time you go out, don't just go out to throw go out to work on something," said Mathieson.
Mathieson has been one of the lone bright spots for a Reading team who has seen its share of early season struggles. The pitcher, believes though that this team is better than its early season record and he hopes to be part of that turnaround.
"We're starting to come around. It's always tough when you start the way we did, but we have a good team. I'd bet money in a month from now we'll be well over .500," said Mathieson.
Mathieson is a confident young pitcher who with time and consistency could be a vital part of the Phillies starting rotation in the near future.