Teheran spent the offseason working to regain a more consistent feel for his slider, Mark Bowman of MLB.com reports.
After an inconsistent 2017 campaign, Teheran is looking to rely on his secondary offerings more in 2018. The 27-year-old saw his slider usage drop from 26.3 percent in 2016 to just 19.4 percent in 2017, which may help explain the similar drop in his strikeout rate (from 22 percent in 2016 to 18.6 percent in 2017). He's also looking to incorporate his changeup more often this season, as it's consistently been his least utilized secondary pitch. While Teheran is hoping his offseason adjustments will help him bounce back in 2018, it would be wise to wait and see how his stuff looks this spring before putting faith in him, as he's still a risky investment.