Following the recent announcements regarding Rockstar Energy Husqvarna Factory Racing's Zach Osborne, the reigning 450 Class Champion, and Monster Energy/Star/Yamaha Racing's Jeremy Martin, the attrition list for the GEICO Motorcycle High Point National has grown even further.

Following a practice crash in the week leading up to High Point, Troy Lee Designs/Red Bull/GASGAS Factory Racing's Michael Mosiman will not suit up for the third rounds of the 2021 season. 

Additionally, Monster Energy/Star/Yamaha Racing's Nate Thrasher underwent a minor surgical procedure prior to High Point. As a result, Thrasher will be forced to watch the action from the sidelines.

After electing to sit out the Thunder Valley National with an illness, Monster Energy/Pro Circuit/Kawasaki's Seth Hammaker will take some additional time away from the track in an effort to ensure he's at full health. As a result, the Pennsylvania native will miss out on his first opportunity to race in front of the home state fans.