Rain and other car issues affected Force India's testing in Italy recently but Paul said at least they have basic knowledge of the new developments in the car ahead of the start of the European season.
"We didn't do a massive number of laps but it was a chance to start evaluating some of our car developments. There's still plenty of work to do in free practice to get on top of the car, but we've already done the basic checks," the Scot said.
"I probably know Barcelona better than any other track on the calendar. We did two tests there in the winter and I had four days in the car so I already feel quite well prepared, but it's the same for everyone. I expect the field to be incredibly close once again," Paul added.
Nico Hulkenberg said the circuit was quite challenging, especially the first three corners.
"The first sector through turns one, two and three is tricky and you need to treat them as one corner. A mistake in one or two will hurt you through three and cost your laptime." MORE