The Basque side face the Catalan giants in Friday night’s final at Atletico Madrid’s Vicente Calderon, having lost to Los Rojiblancos in a Europa League final they had been tipped to win.
Marcelo Bielsa’s entertaining side have become the neutrals’ favourites this season with their direct attacking style, not to mention the choice of football purists because of their policy of only selecting local players.
"There is no pressure on Athletic to win – even if they did lose the Europa League final," Ferrer said in a webchat with Eurosport’s Spanish website.
"They have had a really good year, and have shown that their game is not just about running and working, but also skill and great combination play.
"You cannot forget that this team has come on leaps and bounds in just one year. They have done really well and I hope that they can keep hold of their best players and build on this success."
Los Leones won the hearts of many with their Europa League victories over Manchester United and Schalke, particularly after outplaying United both home and away.
Their league form has been somewhat patchier, and their 3-0 defeat to Atletico in Bucharest particularly disappointing.
Ferrer believes this is down to the high-octane style they employ, which takes its toll on their relatively small squad.
"Because of their style of play, Athletic’s success depends on the physical condition of their players," Ferrer said. "They are very direct and to fulfil their potential they have to be able to give their all, physically.
"In the Europa League final I think they were spent, energy wise. But they have had a chance to rest for the Copa del Rey final and, given how difficult it is against Barcelona at the best of times, I hope they are able to play their own game.
"I wish they could play with that intensity all year round."
Athletic continue to confound with their uncanny ability to stay in the Primera Division – usually with some comfort – despite only drawing on Basque players.
Such a policy makes them utterly dependent on what the local talent pool produces – even now many of the fringe squad members around the first team are effectively Segunda Division players performing above their ability.
This season saw them step up a level to become contenders for the Champions League places, although they ran out of steam towards the end of the campaign when it became clear their best hope was in the cups.
Much of the credit lies with coach Bielsa, always adventurous and sometimes eccentric, who was briefly tipped to be the next Barca manager before they chose to promote from within.
Ferrer had praise for the Argentine tactician, but remains unsure if he has what it takes to succeed with a big club.
"I believe he is a top coach, but it’s hard to know how successful he would be with greater expectations. We’d have to see how he fares with a ‘big’ job."