According to the official MotoGP website, the Spaniard will "step in for the injured Karel Abraham" at the AB Motoracing Open class Honda team.
Abraham has been absent since surgery for a left toe dislocation suffered during a free practice accident in Catalunya on June 13.
After a deal for home star Michael van der Mark fell through at Assen, Abraham was replaced by Honda test rider Hiroshi Aoyama at the Sachsenring.
Elias claimed his only MotoGP race win in one of the most dramatic events of the four-stroke era, at Estoril in 2006. It remains the last victory for a rider outside of a factory team.
After five more podiums on satellite Honda and Ducati machinery over the next three seasons, Elias signed up for the inaugural year of the Moto2 class, winning the title. That led to an unsuccessful return to MotoGP, before swapping back to Moto2 in 2012, where he also mad e three stand-in rides for Pramac Ducati.
Following another tough season in Moto2, Elias made an impressive World Superbike debut in late 2013, netting him a full season ride with Red Devils Roma Aprilia for the next year and a best finish of fourth.
The 32-year-old Spaniard was then due to join the non-starting JR BMW team this season, resurfacing at the Moriwaki team in last weekend's Suzuka 8 Hours endurance race (pictured).
Riding alongside Ratthapark Wilairot and Tatsuya Yamaguchi, the team had been in contention for a podium until technical troubles.
"Good Start, Good Pace and Good Race!" Elias posted on Instagram. "Fighting for P5/P4 before Stoner crash... after we were fighting for P3... very unlucky when technical problem stop us in the garage at 3rd hour, losing 6laps. After we came back from p60 and finishing this amazing experience in p14!
"I have no words to explain what is Finish 8hours race and see what is the final show. What a b ig emotion. Thanks to All Toho racing with Moriwaki staff for this great job and let me feel all this nice things after 10 months without racing! I'm ready to ride again!! I want come back 2016 and fight for the podium again, would be fantastic!!!! Thanks to all my sponsors!! Big hug to all fans!!"
