Najar was the 2017 Argentina national champion.
2018 Vuelta a San Juan Najar won the 5th stage of the
2018 Vuelta a San Juan. Heading into the 5th stage, he was in 14th place, but after the stage he had over a minute lead. However, he was later stripped of his win; in May 2018, Najar tested positive for the third-generation EPO-based blood booster CERA on January 21 - the day of the opening stage of the 2018 Vuelta a San Juan. He was given a four-year ban. ==Major results==