Tottenham star Son Heung-min responded to chants from the club's supporters during the 1-0 win over Manchester City, which were directed at star striker Harry Kane.
The England captain is seeking a move away from Spurs, with Manchester City holding the strongest interest in his services.
Kane was not involved as Spurs bested City on the opening weekend of the season, with Son scoring the winner in the second half.
At one point in the game, Spurs fans were heard singing: "Are you watching Harry Kane?"
Son told Sky Sports: "We are all professional and just wanted to focus on this game, it doesn't matter who is involved and who is not. Everyone was really, really focused for this game.
"Harry is so, so important for us, but let's see and let H prepare well for this season."
On the singing, Son said: "Obviously I was so focused so I couldn't hear it. As I said, we are so professional.
"We just wanted to focus on this game because last season we didn't start well against Everton so we really wanted to start well, especially this season.
"We did a great job and I just want to enjoy this afternoon."