Argentina star Lionel Messi explained his desire to get to the 2018 World Cup in the best possible condition was why he was being rested by the national team.

Messi helped Jorge Sampaoli's men to a 1-0 friendly win over Russia on Saturday, but he will skip their next clash – a meeting with Nigeria.

The 30-year-old, who has scored 16 goals in 17 games in all competitions for Barcelona this season, said a busy run of games meant he needed a rest.

"We talked to him [Sampaoli]. We play many games in the season – the Champions League, the Copa del Rey, LaLiga, plus everything about the national team and the trips," Messi said.

"I want to get to the World Cup in the best way."

It took until the 86th minute for Argentina to beat Russia as Sergio Aguero struck his 35th international goal.

The goal took the Manchester City star into equal third with Hernan Crespo for most goals for Argentina, and Messi was happy for his friend.

"It's nice and important for Kun to score goals," Messi said.

"I'm happy for him. He's been making a lot of goals for City and now he's doing it in the national team.

"I love it."