Red Bull junior Gasly set to replace Kvyat at Toro Rosso in Malaysia

Although there has been no official confirmation from the Faenza-based team, multiple sources have suggested the swap will be made in time for this weekend's race at Sepang.

It is understood that Red Bull chiefs have decided to give Gasly an early try out in a race seat to evaluate his credentials for a full-time drive for 2018.

Previous rumours had suggested Gasly might be in line to step up to a race seat in Malaysia as a replacement for Carlos Sainz Jr, if the Spaniard had been able to complete an early switch to Renault.

However, with Jolyon Palmer standing firm that he wants to see out the season with the French manufacturer - and having eased pressure on himself with a points-scoring finish in Singapore - there is now no opportunity for Sainz to move early.

Sainz's career-best fourth place finish in Singapore has also meant that Toro Rosso is reluctant to let him go, because it is in the middle of a close fight in the constructors' championship with Williams and Renault.

Thanks to Sainz's Singapore result, Toro Rosso is now just seven points behind fifth-placed Williams, with Renault a further 10 points back.

With Sainz staying put, sources have suggested that Toro Rosso has instead decided that Kvyat will be rested for now, to give Gasly a try out in a race seat.

There are suggestions that the Red Bull junior will contest both the Malaysian and Japanese Grands Prix, but will be unable to race at Austin because it clashes with the final round of the Japanese Super Formula championship in which he is competing this year.

Kvyat would then likely be slotted back in for that race, but it is unclear what Red Bull would plan to do for the remaining events of the season in Mexico, Brazil and Abu Dhabi.

The Russian has had a frustrating season, having scored just four points this year through a brace of ninth place finishes in Australia and Spain.

This compares to the 48 points that team-mate Sainz has scored.