Lionel Messi said he hoped his injury scare was "nothing serious" after receiving treatment for a right thigh problem during Argentina's hard-fought 1-0 Copa América win over Chile on Tuesday at MetLife Stadium in East Rutherford, New Jersey.
Holders Argentina qualified for the quarterfinals with their second win of the tournament, thanks to substitute Lautaro Martínez's 88th minute goal.
However, the result was tighter than the world champions would have liked, and captain Messi needed treatment from physios during the first half.
"It's bothering me a bit, but I was able to finish the match," Messi said, speaking in the postmatch mixed zone. "I hope it's nothing serious. It was hard for me to move freely. Tomorrow we'll see how I feel."
Messi still delivered an impressive performance, hitting the post in the first half.
"We knew it would be very physical," he said. "All the games are physical, and Chile are tough. They had a lot on the line ... but we achieved our objective, winning and we're into the quarterfinals."
Argentina are the first nation to qualify from the groups, with one game still to play, facing Peru in Miami on Saturday.
"We deserved to win," coach Lionel Scaloni said. "The game wasn't easy. We won it at the moment you least expected it. The team kept believing and attacking. The win is deserved because Argentina made all the effort, but it was very tough."
Forward Martinez has scored five goals in his past five games for the national team -- and in both Copa América matches -- but started on the bench against Chile, with Julián Álvarez keeping his place.
"Lautaro and Julian can play together," Scaloni said. "It's about finding a balance. Today, Lautaro scored the goal. He's the first who's happy. Julian is the second and I'm the third."
"These games are tough. We have to keep playing this way, it's going to be difficult," Martinez said. "[Chile] sat back, with a line of five, but we're happy because in the end we got the three points. It's a relief, I play for my family, they suffer, so I'm happy."
Chile will need to beat Canada in their last group game to qualify for the next round after Canada beat Peru 1-0 earlier on Tuesday.