Cyril Abiteboul has dismissed suggestions Red Bull will take a significant power unit upgrade at the Azerbaijan Grand Prix and says Renault will not introduce a major update until 2018.

Red Bull has lagged behind Formula One rivals Ferrari and Mercedes in 2017, though a substantial aerodynamic upgrade introduced in Barcelona has helped minimise the deficit, with Daniel Ricciardo picking up three successive podiums in the last three races. The Milton Keynes-based outfit had braced itself for three tough races in Canada, Azerbaijan and Austria, but managed an encouraging podium finish in Montreal.

It is set to be bolstered further by an engine update -- originally scheduled for Canada -- in Baku, as Red Bull targets a return to form during the second half of 2017. However, Renault engine boss Abiteboul moved to clarify the power unit situation at the Canadian Grand Prix and ruled out talk of a "major upgrade" on the scale of the French manufacturer managed at the Monaco Grand Prix last year.

"It was Red Bull who said that there would be an upgrade [in Baku]," Abiteboul told the official F1 website. "There are upgrades permanently -- every single race we are making some small improvements. Last year we created a huge expectation and we came with an upgrade that had a big impact. But we can't repeat that every year."

Red Bull team principal Christian Horner had previously joked the team had been "going to church every week to pray" for a swift update from engine supplier Renault. Abiteboul says there will be no "magic bullet", but regular small updates to provide performance and reliability improvements between now and the end of the season.

"Now it is all about constant improvements which overall will make a difference -- but there is no magic bullet. Every race the engine will become more and more reliable with the program on the dyno progressing. Frankly the next big upgrade will be next year. Then we will have a completely new concept. That will make a difference -- but as I said 2018."