According to a report in Germany's Bild newspaper, Red Bull's patience with engine supplier Renault is running out.
While the reigning Constructors' Champions have seemingly recovered from their disastrous pre-season tests, Red Bull advisor Dr Helmut Marko insists that Renault's power unit isn't performing as they expected.
Marko claims that much of Red Bull's improvement in the last couple of weeks is due to a crisis meeting that took place at Renault's headquarters in Viry, where engineers from the Milton Keynes as well as Toro Rosso were present.
Nevertheless, Marko says that Red Bull's patience with Renault is slowly running out.
"If there is no noticeable improvement in two or three months, we will definitely be talking about an alternative," said Marko, a close friend Red Bull owner Dietrich Mateschitz, told Bild.
He added that Red Bull are working on ways in which to compensate for the 80 horse power advantage Mercedes have over them, but admitted that a more likely scenario would be Lewis Hamilton and Nico Rosberg taking points off each other.
"We cannot put additional horse power in the engine ourselves," Marko added.
"But we can hope for trouble between Rosberg and Hamilton and drive past them."