UFC’s Brian Ortega Offers to Fight Gennady Golovkin, ‘I’m Down!’

If Conor McGregor can fight Floyd Mayweather … why not Brian Ortega vs. Gennady Golovkin?!  The UFC rising star tells TMZ Sports he’s all the way down to take Canelo Alvarez’s place in the May 5 boxing match … now that Canelo has withdrawn…