Each and every spring, fans and teams alike pay extra attention to the radar gun. With the new year underway everyone is anxious to see who has added velocity and -- probably more urgently -- who is missing velocity. Missing velocity is a pretty good indicator of age-related decline or injury. Arizona Diamondbacks ace Zack Greinke took the mound in a minor league game Thursday morning, and his fastball was sitting mostly in the mid-80s, well below where it usually sits during the season. Last season Greinke's heater averaged 91.0 mph in 2017, down from 92.3 mph in 2016 and 92.4 mph in 2015. Like most veteran pitchers, Greinke's velocity has gradually been trending down for years now, since peaking at 95.2 mph way back in 2007. He turned 34 in October and it is completely normal for a pitcher in his mid-30s to lose some velocity. That said, dipping into the mid-80s is always a cause for concern, even in spring training.