Russian player Anastasia Potapova should not publicly support her country during its invasion of Ukraine, world number one Iga Swiatek has said.
Potapova wore a Spartak Moscow football shirt to her Indian Wells match before her three-set loss to American Jessica Pegula on Sunday.
The Russian, 21, said she had supported the club since she was 13 and saw no provocation in it.
"To be honest, I was surprised," Poland's Swiatek said.
"I thought the player realised that she should not, even if she is a fan of the team, show her views in this way at such times.