The Spanish outfit, who finished eighth in La Liga last season, will visit Fratton Park in Pompey's final match before their League Two campaign begins.
"All the Football League clubs start on the same day, so there's a lot of demand for an attractive final friendly. To get a team from La Liga who finished eighth last season shows that we've done well," Whittingham told the club's official website.
"Everyone enjoys the way Spanish sides play football and I'm sure they'll provide a good test for our players."
Portsmouth were relegated from League One last season.