The Queens Park Rangers favourite responded frankly to the current captain on social media.
It all started when Barton, QPR's current captain and midfielder, spoke of his loyalty to the west London club amid reports of interest in him from Marseille.
Barton's agent was said to have spoken to the French club, to which Marsh responded with the advice that Barton should sack his representative.
The R's man replied the only way he knows how: with fighting talk. The pair then traded insults before former QPR forward Marsh seemed to land a relative blow to the 32-year-old.
Newcastle United boss John Carver, meanwhile, feels Barton and co will have a point to prove against them this weekend.
Little will it matter, though. Barton's campaign with the R's has been summed up by his social media spat with a club icon. Big on Twitter. Not so much when the going gets tough.