Nationals' reliever Blake Treinen's 2015 season was one of extreme highs and lows. After succeeding in multiple roles as a rookie in 2014, he struggled with consistency this past season despite pitching full-time out of the bullpen with several opportunities offered to throw in high leverage situations.
One look at his monthly splits for 2015 and it's clear there were different versions of Treinen throughout the year. In August, for instance, he allowed zero runs in 11 appearances and looked revitalized after spending a few weeks at Triple-A Syracuse. But then in September, Treinen had his worst month of 2015 with nine earned runs in 17 appearances across 14 1/3 innings.
Treinen was streaky in 2015, but he thinks another split better tells the story of his second MLB season. That would be his troubles against lefties, who hit .336/.425/.509 off of him, compared to the .187/.276/.493 mark posted by righties.
"Obviously, there were some issues with consistency with lefties and that's to me the biggest glaring issue that I need to fix," he said. "There were times when things went really well and there are times when things went pretty darn bad. The consistency side of things is my biggest focus in the offseason."
Treinen wasn't great against lefties in 2014, as they held a .798 OPS off of him. But that's still much better than the .931 OPS-against left-handed batters recorded in 2015.
One thing that was pointed out by Treinen and manager Matt Williams throughout the 2015 season was Treinen's need to keep is fastball down, especially when throwing inside to lefties. His heatmaps from 2014 and 2015 help demonstrate that.
Here is a look at opponent's slugging percentage vs. Treinen. Notice the difference in success on pitches thrown inside from year-to-year:
Treinen's inside pitches were being teed up on by lefties and that frustrated him. Of the 14 extra-base hits he allowed in 2015, 12 of them were to lefties.
"You make good pitches sometimes and they put hits on it, and [sometimes] you make terrible pitches and they make you pay for it. I think it's a matter of knowing how to attack a little better and executing those pitches," he said.
Treinen is determined to show the Nationals that 2015 was not indicative of the pitcher he can ultimately be.
"I'm just looking forward to being better prepared and showing the team that's just one blip of a year and it's not going to be an issue anymore," he said.
Treinen was given chances in a setup role in 2015, but was never fully able to convince Williams he was worthy of a permanent late-innings job. He knows there could be opportunities again in 2016 for high leverage situations, but he is not concerned with all of that at this point.
"I'm not worried about roles and I don't think anybody on this team is. You can't get caught up in it. If we just go out and pitch to our abilities, the team and the organization is going to put us where we are best-suited to help this team win," he said.