The team was thumped by Geelong on Friday night to have its season ended.
Robinson later took to Instagram to post a photo of himself after a different game, in which the Lions beat Richmond at the Gabba.
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In his comment, he took aim at Fagan for supposedly not allowing him to announce his retirement in a press conference.
“This was my last photo as a Lion. Happy beating the Tiges but sad knowing it’d be my last at the Gabba,” Robinson said.
“Devastated Fages wouldn’t allow me to announce this in person to the supporters and my teammates, but I guess that’s footy… it’s been an absolute privilege pulling on the Fitzroy and Lions jumper!
“Thank you all for the last eight years, I’ll never forget the love you all showed me, Emma and my kids.
“I left it all out there every single game, I love you all.”
The 33-year-old played 247 senior games across Carlton and Brisbane.
He moved to the Lions at the end of 2014 after a 100-game stint at the Blues – now becoming the only AFL player to be delisted twice after playing 100 games at two different clubs.
Robinson was the Lions’ joint best and fairest winner in his first season at the club in 2015.
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