For both these clubs it will be a chance for their first piece of silverware at the end of long and frustrating seasons.
Barcelona surrendered their La Liga crown to Real Madrid and bowed out of the UEFA Champions League in the semi-finals, while Athletic Bilbao were beaten in the final of the Europa League by Spanish rivals Atletico Madrid earlier this month.
The bookies expect it will be a case of third time lucky for Barcelona, with Luxbet installing the Catalan giants as a short-priced $1.26 to win the 2012 Copa del Ray, with the draw (after 90 minutes) at $5.50 and Bilbao rank outsiders at $8.75.
These two clubs are the two most successful in Spanish Cup history with Barcelona having lifted the trophy on 25 occasions, the last time in 2009. They were beaten in last year's final by Real Madrid.
|Back Barcelona to beat Athletic Bilbao in the Copa del Rey final on Saturday morning at Luxbet at $1.26.
||Have a crack at Barcelona winning 4-1 in correct score betting at $13.5 at Luxbet.|
And Bilbao are second on the all-time winners list with 23 (Real Madrid have won on 18 occasions), despite not having won the trophy since 1984.
Bilbao last appeared in the final in 2009 when they were thrashed 4-1 by Barcelona and a similar scoreline could be in the offing this time around as well.
Not only will Barcelona be desperate to end a frustrating campaign on a high, they will want to provide a fitting send-off for departing coach Pep Guardiola in his last match at the helm.
Guardiola has bought unprecedented success to Barcelona in his four years in charge, turning them into the best team in the world before this year's stumbles.
Barcelona also finished eight places and a staggering 42 points better off than 10th-placed Athletic Bilbao during the Spanish league season and have not lost to the Basque club in any of the past 17 meetings dating back to 2006.
So even at $1.26 Barcelona look good and if you are looking for a bit more value why not back Barcelona to lead at both half-time and full-time at $1.70.
For the brave you can get $13.5 at Luxbet if you back Barcelona to win by the same scoreline - 4-1 - that they won by three seasons ago in correct score betting.