Argentina's Lionel Messi and Portugal's Cristiano Ronaldo are both set to play for their countries for the first time since the 2018 World Cup in Russia.
Messi is due to start Friday's friendly for Argentina against Venezuela in Madrid, with Ronaldo in the squad for Portugal's opening Euro 2020 qualifier at home against Ukraine in Lisbon.
Both men have missed six international matches since the World Cup.
Portugal reached this summer's Nations League semi-finals without Ronaldo.
The 34-year-old has scored 85 goals in 154 international games and could also play in Portugal's game in Serbia on 25 March.
Portugal defender Joao Cancelo, Ronaldo's team-mate at Juventus, was delighted to have him back in the national squad.
"Cristiano adds quality to any team," said Cancelo. "It's a pleasure to play with him and he's very important for us."
Messi, 31, has scored 65 goals in 128 international appearances and, while he is set to play at Atletico Madrid's Wanda Metropolitano stadium, Manchester City's Sergio Aguero, Chelsea's Gonzalo Higuain and Inter Milan's Mauro Icardi are not in the squad.
"It's a joy for me and for everyone that he's back - we're all very happy," said Argentina boss Lionel Scaloni of Messi's return.
The news Messi has ended his self-imposed exile from international football also pleased Venezuela coach Rafael Dudamel.
"The presence of the best player in the world lifts the game's expectation," Dudamel said.
"For us to take on Argentina is a good way to see how we stack up. The return of Lionel Messi makes the demands on us extremely high."
ChelseaQueen1
136
The truth is that these two legends make their teams and teammates better👌
lukzlat910
115
Pele watching Messi's performance and will start criticizing when Messi makes at least one mistake but will go into hiding once Messi scores
Irfan19
90
Both thr GOATs coming together to save their national team. Hope Ronaldo wins the Euro2020 and Messi the Copa America 2019.
Nibdnprst
67
good luck only goat
datsama
60
messi. 5 ballon d'or ronaldo. 5 ballon d'or. messi. argentina all time highest goal scorer, ronaldo. portugal all time highest goal scorer. messi self-imposed exile from the national team after the world cup ronaldo self imposed exile from the national team after the world cup. ronaldo 8 hack tricks in the champions league. messi. 8 hattricks in the champions league. so if they don't want to compare each other why must we compare them? let's just watch them and enjoy the privilege we have...
XAGAR
50
I'm real Madrid fan but i wish all good luck for Messi in copa America hope he will win