Adam Yates will race alongside twin brother Simon in La Vuelta, Australian team Mitchelton-Scott have announced.
Simon had long planned to take part in the final Grand Tour of the season following his starring role in the Giro d'Italia in May, but a change to Adam's race program will see him head to Spain as well after he fell short of his targets in the Tour de France.
The team plan is for Adam to ride in support of Simon, who will be the designated leader at the race which starts in Malaga on August 25. It is rare for the 26-year-old twins to compete in the same race, though they both started their seasons at the Volta a la Comunitat Valenciana.
"The Vuelta a Espana wasn't originally on my program but together with the management we came to the decision that doing the Vuelta after the Tour would be another good chance to get some experience in riding multiple Grand Tours in one year," Adam said.
"It's pretty difficult to replicate the fatigue of a Grand Tour in training so the opportunity of riding the Vuelta without the stress of riding GC will be a good step towards gaining more experience not just in racing over three weeks but also in following all the routines and day-to-day stuff that goes on in a Grand Tour."
Adam finished fourth in the 2016 Tour, winning the young riders' classification, but cracked during the Alpine stages in this year's race - something he put down to dehydration - and ultimately finished over an hour behind winner Geraint Thomas in 29th place.
Simon spent 13 days in the leader's pink jersey at the Giro in May, but faded badly on stage 19 as Chris Froome launched an audacious attack which propelled him to overall victory.
He will again target the general classification but both brothers, who recently signed new two-year deals with the team, are also looking towards September's World Championships in Innsbruck.
Simon said: "My preparation has been very different to the Giro d'Italia because like a few guys that will line up in Spain, I have one eye on the World Championships later this year so it will be interesting to see how my body responses but as always I'll give it my all to achieve a great result."