Marquez has been out of action since breaking his right arm at the late season opener in Jerez in July.
A failed attempt to return for the Andalusian GP the following week aggravated his injury and resulted in a lengthy break on the sideline.
The six-time champion has since undergone three surgeries, the last of which was in December when a bone was transplanted from his hip to his humerus.
The Spaniard did not recover enough for the start of the 2021 season, however, as he missed the pre-season tests as well as the first two rounds of the season in Qatar last month.
Honda test driver Stefan Bradl replaced Marquez at both events and achieved a top 11th place in the first of the two Doha races.
In a statement released Saturday morning, Honda said doctors had given Marquez the all-clear to contest the third round of the season in Portimao from April 16-18.
“In the examination that the medical team of Hospital Ruber Internacional carried out four months after the operation on Marc Marquez, under the direction of doctors Samuel Antuña and Ignacio Roger de Oña and consisting of doctors De Miguel, Ibarzabal and García Villanueva, because of an infected pseudoarthrosis The right humerus showed a very satisfactory clinical condition with clear progress in the bone consolidation process. In the current situation, Marquez can return to competition, taking the appropriate risk of his sporting activity, ”the statement said.
Marquez’s recovery was delayed by an infection contracted during his second surgery in August that followed weeks after his abandoned comeback attempt in Jerez.
Despite not having to test a MotoGP bike since his injury, Marquez has ridden the Honda RC213V-S test bike in Barcelona and the Algarve in preparation for his return to the race.
The Spaniard also has a new teammate in 2021 with former KTM rider Pol Espargaro after brother Alex Marquez joined the LCR satellite team alongside Takaaki Nakagami.
“I’M VERY HAPPY!” Wrote Marquez on Twitter. “I visited the doctors yesterday and they gave me the green light for the competition. It’s been 9 difficult months, with moments of uncertainty and ups and downs, and now I can enjoy my passion again!
“See you next week in Portimao!”
Honda has had a difficult start to the new season, with the Repsol-supported works team in fifth place after the first two races.
Espargaro finished the first two races in eighth and 13th.