However, an official FIA statement revealed that the alleged infringement actually happened during FP2 on Friday afternoon.
Thankfully for the Spaniard, the FIA confirmed that there would be no further action taken against him, as with Franco Colapinto in the Alpine who was under investigation for a similar alleged infringement.
Any grid drop penalty around the Monaco street circuit could be fatal for a driver's race weekend, with qualifying being so crucial due to the narrow, windy nature of the Monaco track, which makes it very difficult to overtake during the race.
Sainz hunting more points
Following a difficult start to his Williams career, Sainz has managed to get in amongst the points-scoring positions in recent races, currently sat in 11th in the drivers' standings with 11 points.
Sainz's team-mate Alex Albon has been in scintillating early season form, buoying the team into fifth place in the constructors' championship.
The Spaniard will be hoping for more points this weekend, following a good result last time out at the Imola GP.