The Canadian, who has recently been in trouble with stewards for his reaction to being knocked out of Q1 at the Qatar GP, caused Sainz to get onto the kerb and spin around, having not seen the Spaniard on his flying lap and being clearly in his way.
Although it was announced shortly after the session that no further investigation would be needed, the incident summed up Stroll and Aston Martin's poor start to the weekend, where they have looked off the pace at the Autodromo Hermanos Rodriguez.
The incident surely would have been a slamdunk penalty if it had taken place in qualifying, with Sainz completely ruining his tyres, and almost being collected by the barriers after spinning whilst trying to avoid Stroll.
Sainz rages at Stroll
The Spaniard wasn't the only Ferrari driver who was left feeling aggrieved during the session.
Charles Leclerc also felt he was impeded, by Haas' Kevin Magnussen who admitted over his team radio that he hadn't seen the Monagasque driver, attempting to blame his engineer for not letting him know he was there..
Neither Stroll nor Magnussen will pay the price for the FP3 incidents, but Sainz was left unimpressed by Stroll's inability to get out of his way.
“This guy. Honestly, this guy," he complained.
"If that’s not a penalty. He couldn’t do that in Practice.”