MotoGP could have two Marquez brothers on the grid in 2019 after Alex set out his aim to join world champion Marc in the elite class.
Since arriving in MotoGP in 2013 Marc has been a league above his rivals, winning four titles in five seasons with Repsol Honda.
While Marc has been dominating the sport, Alex has been forging his way in the lower classes - winning the Moto3 title in 2014 before stepping up to Moto2.
After taking time to adjust, the 21-year-old finished fourth in the standings this year and his improvement was rewarded with a private test on the Marc VDS MotoGP bike in Jerez.
The Spaniard impressed with some good times and hopes it is the start of his progression to being a regular member of the paddock, challenging his brother.
"In the end it's a motivation for me to have this experience, to try and win in Moto2 and to try and move to MotoGP in 2019," said the younger Marquez.
"But now I need to focus on the winter and the first test with Moto2. I'll have to forget a little bit this experience that was really nice."