Suzuki admitted that a 'misunderstanding' of the rules led to Sylvain Guintoli using a prototype 2020 engine during Friday practice for the Japanese MotoGP.

The wild-card was subsequently disqualified from both Friday sessions by the FIM Stewards, having contravened of the Grand Prix Regulations, which states:

Wild Card entries using machines from an MSMA manufacturer currently entered in the MotoGP class are subject to all technical regulations related to their specific manufacturer, including engine specification, ECU hardware and software, sensor approval and free device checking.

In other words, a change of engine specification is not allowed during the season.

No attempt was made to conceal Guintoli's new parts, Suzuki confirming use of a prototype 2020 engine in their own Friday press release, with Guintoli saying: "We’re working on our 2020 engine and already we’re getting positive feelings, data, and feedback. Today my lap times weren’t bad, and I managed to set my best lap in Motegi, so that felt good."

As such, the team clearly thought the engine modifications were legal for a wild-card rider and team manager Davide Brivio stated on Saturday evening: “Yesterday we had a misunderstanding in regard to the regulations which meant that we had to swap the engine on Sylvain’s bike this morning."

Guintoli, who had been 20th on Friday, went on to set the fifth-fastest time in the wet Saturday morning session before qualifying 21st in the dry.

Regular Suzuki riders Alex Rins and Joan Mir will start Sunday's race from eleventh and twelfth respectively.

“I’m a bit disappointed because I fought hard to come through Q1 and then I couldn’t fulfil the potential in Q2," said double 2019 race winner Rins. "I will start from 11th tomorrow and I will attack, ‘full gas’, to give Suzuki a good result at home."

“I wanted a bit more out of today, I knew I could do better," added rookie Mir. "On the last laps in Q2 the track was drier, and my feeling was so much better, but then I went wide on my last flying lap and I lost some time. I’m really looking forward to tomorrow and I’ll give my all to fight with the front group.”

Suzuki is known to be seeking a top speed increase for 2020, albeit without losing the GSX-RR's strong cornering ability.