Barcelona ace Neymar was embroiled in a row with a Manchester City fan after Tuesday's 2-1 Champions League win for the Catalans at Eastlands.
Neymar confronted the young man who appeared to make a diving gesture at the Brazilian in a video that has surfaced online.
However, stewards were on hand to separate the duo following a brief verbal exchange immediately after the full-time whistle at the Etihad.
Match officials missed the incident but it could land the 23-year-old in hot water with UEFA if the Premier League side decide to report the spat.
Luis Suarez grabbed a brace as the Catalans secured a narrow advantage in the last-16 tie, with Sergio Aguero reducing the arrears on 69 minutes.
Their comeback bid was then halted as Gael Clichy was sent off for a second yellow card, but Joe Hart threw City a lifeline by saving Lionel Messi's stoppage-time penalty.
The tie will resume at Camp Nou on March 18.
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