Eddie Irvine yesterday dismissed suggestions that he is under pressure from new Jaguar team-mate Pedro De la Rosa, despite pushing his R2 to second fastest in free practice ahead of tomorrow's Spanish Grand Prix in Barcelona.

The Irishman who has struggled with a difficult car all season found an extra reserve of pace in the latter stage of yesterday's afternoon session to eclipse Spaniard De la Rosa who had minutes earlier clocked seventh fastest time of the day while Irvine was languishing near the foot of the times.

Irvine denied that had felt any pressure to up his game in the light of the former Arrows driver's opening day performance.

"I never felt that at all," said Irvine afterwards. "Pedro's been testing with us for a while and I know his pace from that to be honest."

The seventh-placed Spaniard yesterday admitted he had enjoyed his first competitive run in the R2 adding that he was surprised by Irvine's sudden pace.

"Friday times are not important really," said De la Rosa. "The only important thing is what you learn about tyres and how the car is working. As for the positions, if I'm seventh and Eddie is second then that definitely is an improvement and if that spurs the team on then that's good. Still, I hope he isn't that quick all the time."

The Jaguar number one also conceded that while yesterday's pre-race preparation represented a major step forward, thanks to new race team manager Mark Ellis, the performance will not be repeated in qualifying.

"There's no mystery to it," he said. "There's only one thing you can do on a Friday to make a car go quick and you won't stay in that position on Saturday, so I think we'll be back to where we normally are in qualifying."

While the Jaguar drivers sparred with each other it was McLaren's David Coulthard who took up station at the top of the timesheet. The Scot is looking to consolidate his championship charge and better three consecutive second places at the Circuit de Catalunya.

Coulthard ended the day an encouraging half second clear of Irvine and, better again, was seventh tenths quicker than championship co-leader Michael Schumacher.

Schumacher though has been hampered, as have many teams by the adaptation to the new traction control systems being run this weekend for the first time since the technology was made illegal in 1993 and contrary to most of the pre-race speculation that the implementation of the new systems would alter little this weekend, it has become clear that some teams are struggling with the systems that have yet to be fully developed.

While Schumacher insisted that Ferrari had no problems to report and that the team had done intense work on their system prior to this weekend, his younger brother Ralf struggled with his Williams FW23 and team owner Frank Williams later admitted that the team was having difficulty with the systems.

"We are not fully up and running with our traction control yet," he said. "We ran it in limited form today and we have to realise that developing it will be an ongoing process for BMW."

Williams' difficulties could once again play into Jordan's hands, though 10th place for Jarno Trulli and 14th for Heinz-Harald Frentzen yesterday does not bode well for progress in this afternoon's qualifying session.

"It was a routine Friday," said Trulli, "although I did lose most of the morning session with a clutch problem. It was very windy on parts of the track, which affected the balance of the car, which might explain why it doesn't feel so great at the moment. We also had to make some electronic adjustments to fine tune the traction control."

"I made a mistake and went off in the same place twice, so I'm obviously not too happy" said Frentzen in explanation of his 14th place. "I'm trying to find a better set-up to cope with that corner, but we're confident we're heading in the right direction. We've completed a lot of testing with traction control but it still takes time to get used to it in the sense of learning what advantages it brings in lap times and in terms of tyre degradation."

While Jordan fine tune their race programme, Benetton may find their weekend going from the bad of 18th for Giancarlo Fisichella and 19th for Jenson Button yesterday to the infinitely worse of having to use a stand-in driver for Button this from morning.

The Englishman has been complaining of a damaged shoulder for some weeks and yesterday claimed the situation had become worse as he tried to muscle his B201 through Barcelona's demanding corners.