BRADENTON, Fla. -- Pirates Twitter was abuzz over Tyler Glasnow's Grapefruit League start Sunday against the Red Sox at LECOM Park, although the hubbub wasn't so much about his pitching line as his repertoire.

To get to the point: Was Glasnow mixing in a cut fastball?

He's never thrown one in his major-league career, as far as pitch-tracking technology can tell, but there was discernible glove-side movement on several of Glasnow's fastballs while he navigated 4 2/3 innings of one-run ball in Boston's 2-1 win.

That fact, combined with the fact that Glasnow's fastball velocity occasionally dropped into the low 90s led many fans on social media to speculate that he was putting a new pitch into play while also trying to put his best foot forward before opening day.

However, Glasnow...

To continue reading the rest of this article, subscribe to Pirates Prospects. Subscribers get access to every article on the site, along with all of our exclusive live coverage of the Pirates' minor league system, all for a very low monthly or yearly rate.

If you're already a member, you can log in below. If you think you're receiving this message in error, please e-mail tim@piratesprospects.com.