Celtic striker told the 19-year-old Millwall loanee 'this is why you're at St Johnstone ' in a scathing on-air snipe at his tackle on Ryan Kent.
Muller brought the winger down in the box with a sliding challenge that allowed Kemar Roofe to step up and cancel out Michael O'Halloran's opener for Saints.
James Tavernier then smashed in a stunner to win it for Steven Gerrard's side but Hartson reckons Muller's foul was the turning point. Get all the latest Rangers news sent straight to your Inbox every day by signing up to our newsletter.We cover every morsel of information regarding your favourite club in the form of articles, videos and podcasts.The newsletter will arrive every day at 12pm, giving you a round up of the best stories we've.
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