By Iain Rogers
MADRID, May 28 (Reuters) - Athletic Bilbao have proudly resisted pressure to abandon their policy of only recruiting players of Basque origin, making it all the more impressive that they are the club standing between Barcelona and a record-extending 27th King's Cup.
Treble-chasing Barca host Bilbao, who are second on the all-time winners list with 23 Cups, in the final on Saturday (1930 GMT) having already wrapped up a fifth La Liga title in seven years.
The Catalan giants can match their unprecedented trio of titles from 2008-09 if they win at the Nou Camp and go on to vanquish Juventus in the final of the Champions League at Berlin's Olympic Stadium on June 6.
Many appear to have already written off Bilbao's chances but they have again proved this season that on their day they are more than a match for La Liga's heavyweights.
They beat Real Madrid 1-0 at the San Mames in March and ended their latest La Liga campaign in style last weekend with a 4-0 drubbing of Villarreal that secured seventh place and a berth in the Europa League for next season.
They are playing in their third domestic Cup final in seven years -- they lost to Barca in 2009 and 2012 -- and Barca centre back Javier Mascherano knows Saturday's clash will not be the stroll that some seem to believe.
"Athletic are a Cup team par excellence and they are going to make it very tough for us in the final," the Argentina international told television broadcaster Canal Plus this week.
"Maintaining their culture in the global game that is football makes them a special club," he added.
"It's striking that despite all the limitations they are still so competitive.
"It is worthy of all my respect that they still keep this philosophy regardless of results."
Bilbao's chances will likely hinge on whether they can contain Barca's lethal South American front three of Lionel Messi, Neymar and Luis Suarez, who have been scoring for fun since the turn of the year.
Uruguay international Suarez looks to have recovered from a hamstring problem that sidelined him for Barca's final two La Liga outings and trained with his team mates on Wednesday without yet being given the medical all-clear.
Barca may be huge favourites but Bilbao have nothing to lose and if luck is on their side an upset is a real possibility. (Editing by Patrick Johnston)