MENDOZA (Argentina) • Lionel Messi's triumphant Argentina comeback has been tempered by a hint he may not be fit to play in Tuesday's World Cup qualifier in Venezuela.

The forward, who had gone back on his decision to quit the team following their Copa America final defeat in June, scored the only goal in a 1-0 home win over Uruguay on Thursday that sent Argentina to the top of the South American group.

However, the Argentina captain said he had a groin pain and had to think about his fitness at the start of a busy season for his national side and his club Barcelona.

"My groin is hurting a lot, from before this match," he said. "We'll see, I always want to be (in the team) but there are also a lot of important matches coming up."

Messi explained his decision to retire from international football after Argentina's loss to Chile in which he missed his team's first penalty in the decisive shoot-out.

"I didn't deceive anyone in that moment," he said. "I was disappointed because it was a hard blow and I said that because that's what I felt.

"But afterwards, seeing what this group (of players) is like, and with the affection of the fans, I reconsidered."

He is now back gunning for a fourth World Cup appearance in Russia in 2018 with Argentina heading the 10-nation group with 14 points from seven matches.

On Thursday, Messi, showing no sign of the groin injury which had placed a question mark against his participation, lashed home the winner on 42 minutes, with his low shot taking a wicked deflection to deceive Uruguay goalkeeper Fernando Muslera at the near post.

Afterwards the Argentinian paid tribute to the rapturous applause he received throughout. In the dying minutes, one young fan sprinted onto the pitch and nearly flattened the five-time World Footballer of the Year with a congratulatory hug.

"I am grateful to the people for the treatment, for the love," Messi said.

Argentina's new coach Edgardo Bauza saluted Messi's commitment in returning to play despite his niggling groin problem.

The coach hinted Messi may be rested against Venezuela.

"If he's not right we won't risk him," Bauza said. "I know how painful it is to suffer a groin injury."

Argentina's win came after a superb defensive effort in the second half when they had been reduced to 10 men following the dismissal of young Juventus striker Paulo Dybala just before half-time.

Dybala, 22, was escorted from the pitch in tears after the red card.

In other matches on Thursday, Colombia defeated Venezuela 2-0 to move level with Ecuador and Uruguay on 13 points, just behind leaders Argentina.

Paraguay got level on 12 points with Brazil after a 2-1 win over Chile in Asuncion. Bolivia defeated Peru 2-0 in La Paz.

REUTERS, AGENCE FRANCE-PRESSE