Alexis Sanchez took time out from Chile’s preparations for Tuesday’s crunch World Cup qualifier against Venezuela to undergo a drug test.
The two-time Copa America winners’ hopes of securing a spot in Russia are hanging by a thread following the 1-0 defeat in Argentina last week.
Arsenal star Sanchez showed his frustration at the final whistle in Buenos Aires, pulling his shirt over his face after a defeat that could have huge consequences in the CONMEBOL group.
However, he looked far more relaxed on Sunday night when providing samples in the out-of-competition testing for this summer’s Confederations Cup.
Lionel Messi’s penalty was enough to earn the Argentines a vital victory at El Monumental last time out as Chile slipped to sixth place – a massive 10 points behind table-toppers Brazil after 13 games.
Messi fired the winner from the spot after Jose Fuenzalida had pushed Angel Di Maria in the area.
Sanchez struck the woodwork with a free-kick and went close with another set piece as the visitors looked for a leveller.
Meanwhile, Sanchez’s Arsenal future remains up in the air after Gunners boss Arsene Wenger revealed the club had shelved contract talks with their top scorer.
The 28-year-old is approaching the final 12 months of his deal at the Emirates and has so far refused to commit his future to the north Londoners.
Wenger, in an interview with beIN Sports, said: “Look, at the moment we have not an agreement (with Sanchez). We have decided to focus on the end of the season and talk about it during the summer.”