Jeff Alessi will join older brother Mike in Super X for the remainder of 2010.

American Jeff Alessi will join the CDR Rockstar Energy Yamaha team for the remaining rounds of the 2010 Monster Energy Super X, Australasian Supercross Championship.

Alessi, whose brother Mike has contested the entire series for JDR Motorex KTM, will partner Jay Marmont on the factory Yamaha team and commenced testing this week in New South Wales.

“We welcome Jeff to Australia and he comes highly recommended,” commented team owner Craig Dack. “We put both riders through a solid mid week test session and they both looked sharp and ready to go.”

The series will continue this weekend at Auckland in New Zealand, where Alessi will make his race debut on the CDR YZ450F alongside Marmont.

Regular team rider Cheyne Boyd has been ruled out of the series with injury, expected to switch to the factory Honda Racing team for the 2011 season.