Daniel Ricciardo's move to Red Bull puts Webber's replacement under the spotlight too soon

With new regulations and preseason testing already difficult, Red Bull has the added stress of whether Daniel Ricciardo has what it takes to drive alongside Sebastian Vettel.

Although Vettel's relationship with Mark Webber was often difficult, Webber was a driver who guaranteed a healthy haul of points and his retirement from Formula One has left Red Bull with a void to fill.

"It is a huge opportunity and privilege to work alongside a four-time world champion in Sebastian," Ricciardo said. "I am really looking forward to it."

With the constructors' title to defend, Red Bull needs Ricciardo to perform consistently well.

"I would love to be as competitive as soon as possible," he said. "After some time, hopefully not too long, I want the team to know that I am capable of getting some top results."

This is even more the case given how their rivals are shaping up.

Ferrari boasts two world champions — Fernando Alonso and Kimi Raikkonen — and the Mercedes pair of Lewis Hamilton and Nico Rosberg will have gained confidence from last season, winning three races and securing eight pole positions between them and challenging Red Bull for pure speed.

Replacing one Australian driver with another makes for a nice symmetry, but the gulf between Ricciardo and Webber remains huge.

Webber won nine GPs and finished third three times in the championship race, while the 24-year-old Ricciardo is in his third season and his best race finish is seventh. Rivals will hope that a slow start from Ricciardo will impact on Red Bull's confidence and unsettle Vettel over the course of the season.

A strong start on his home track in Melbourne could be just the early boost Ricciardo needs to silence the doubters.

"I won't need much psyching up, Melbourne will take care of that. Being the sole Australian I am sure there will be a lot of attention," Ricciardo said. "People talk about pressure, but for me it is exciting, the adrenaline will be pumping."

How Ricciardo fares in qualifying could also play a factor in how well Vettel does.

Red Bull has been consistent in qualifying over the years, often leading races from 1-2 on the grid and making it more difficult for opponents to get to Vettel. But if Ricciardo is qualifying lower down the grid, this could leave Vettel more exposed to attack.

The problems experienced in preseason testing offer further encouragement to Red Bull's rivals.

"We're definitely not up to scratch with where we'd like to be," Ricciardo said during the final preseason testing in Bahrain recently. "It's clear we probably won't come out to Melbourne and dominate as the team did last year."