Tyler Glasnow has given the Tampa Bay Rays a scare after leaving Friday's start against the New York Yankees with an arm injury. 

Per MLB.com's Juan Toribio, the Rays announced Glasnow's injury as forearm tightness, and he will undergo further evaluation Saturday. 

Glasnow was shaking his arm off after throwing a pitch, then on the following pitch that struck out Gleyber Torres, he signaled for the training staff to come look at him. 

The Rays will be anxiously awaiting the results of Glasnow's follow-up exam. The 25-year-old has been an essential piece in their rise to the top of the American League East. He entered Friday leading Major League Baseball with a 1.47 ERA and an AL-best 0.86 WHIP. 

Tampa Bay acquired Glasnow last July from the Pittsburgh Pirates as part of the Chris Archer trade. The right-hander finished 2018 strong with 64 strikeouts in 55.2 innings after the deal. He found another level to start this season, emerging as a potential AL Cy Young candidate. 

Glasnow, Blake Snell and Charlie Morton have been Tampa Bay's primary starting pitchers. Manager Kevin Cash continues to mix in relievers, including Ryne Stanek and Yonny Chirinos, to start games around his top three guys.