11:47 AM PT -- Rublev isn't the only Russian athlete speaking out against Vladimir Putin's invasion of Ukraine ... 'cause one of the country's most famous and talented athletes, NHL superstar Alex Ovechkin, is speaking out against the attack.
While speaking to reporters, the 36-year-old Capitals star said, "It's a hard situation. I have family back in Russia and it is scary moments." Ovechkin continued ... "But, we can't do anything. We just hope it going to be end soon and everything is going to be all right."
The Capitals captain added, "Please, no more war. It doesn't matter who is in the war -- Russia, Ukraine, different countries -- I think we live in a world, like, we have to live in peace and a great world."
What makes Ovechkin's stance interesting is that he's been an ardent supporter of President Putin ... even campaigning for Vladimir when he was up for reelection several years ago.