As he leads his nation, the 37-year-old hopes to put Manchester United’s poor season behind him.
Ronaldo shared a photo of himself in training with United teammate Diogo Dalot on Twitter.
After missing Manchester United’s last Premier League game of the season due to a hip flexor issue, he rejoined his teammates last week.
However, Ronaldo was seen going through his paces on the grass at Portugal training and showed no signs of injury.
Tomorrow night, Portugal travels to arch rivals Spain to begin their Nations League campaign.
The match will take place at the Benito Villamarin Stadium, which is home to Real Betis.
It’s the start of a hectic international calendar for Ronaldo, who has four games in the next ten days.
The match against Spain is followed by home matches against Switzerland and the Czech Republic, before Ronaldo and his teammates go to Switzerland on June 12.
Champions of the 2016 Euros Portugal has a strong history in the league, having won the first Nations League on home soil in 2019.
At Manchester United, Ronaldo was the club’s savior during their worst Premier League season ever.
However, he has compelled United to upgrade some of the club’s Carrington training facilities.
According to the Mirror, Ronaldo complained about the quality of the swimming pools at United’s headquarters and refused to use them.
His complaints have been taken into account by the club, which has ordered that work on the pools be finished in order to prepare them for pre-season.