Parts of Sauber F1 upgrade package delayed until Monaco GP

Like the majority of teams on the grid, Sauber had planned to bring a big package to Barcelona for this weekend, but its technical department wanted further time to work on some aspects of the new parts.

It has brought a new rear wing, which it evaluated during the post-Bahrain Grand Prix test, along with new front wing flaps and new front brake ducts.

The rest of the package, which will include a new floor, is set to be bolted onto the car at the following race in Monaco.

An update of any sort is still a step forward for the team, which in 2016 did not update its car until the second-half of the season because of a lack of funding.

But the delay means the Swiss team is bracing itself for a difficult weekend in Spain, given the rest of the grid will likely make a step forward with their new updates.

Sauber has struggled to make an impact so far this season and is one of only two teams that has failed to score.

It is believed the team is struggling to optimise its cooling, which is a particular frustration because its early decision to stick with a year-old Ferrari power unit for this season should have helped avoid such an issue.

Despite the delay with upgrades and the cooling issues, Pascal Wehrlein is hopeful Barcelona will be stronger than the last race at Sochi, where the team finished 15th and 16th.

"We have a few updates on the car and for Monaco we have more updates so I'm really looking forward to the next races," said Wehrlein.

"I hope the updates work as expected and we make some progress.

"It will be quite difficult to challenge for points this weekend but we will try our best."