Motherwell will further honour late captain Phil O'Donnell in a home match against Villarreal on 2 August.
The main stand at Fir Park will be named after O'Donnell before kick-off and money will go to an educational trust for his four children.
O'Donnell, 35, collapsed and died of heart failure during a match against Dundee United on 29 December.
Celtic and Motherwell sides played a sell-out charity game in O'Donnell's memory at Celtic Park in May.
Villarreal finished second in Spain's La Liga last season and can boast stars such as Turkish striker Nihat Kahveci and former Arsenal midfielder Robert Pires.
El Madrigal trio Joan Capdevila, Marcos Senna and Santi Cazorla are in the Spanish squad at Euro 2008.
"We are very pleased that Villarreal, who are an outstanding European team and a great club, accepted our invitation to play at Fir Park in this pre-season match," said Motherwell chairman John Boyle.
"It will be an emotional day for everyone associated with Motherwell as we will be renaming the main stand after Phil.
"We hope our fans will turn out in their thousands again to salute Phil and to see us play against superb opposition."
O'Donnell's brother, James, said: "It's a great honour for the main stand to be named after Phil and we appreciate deeply everything that has been done for Eileen and the children by ordinary football supporters and by the club."
The main stand at Fir Park will be named after O'Donnell before kick-off and money will go to an educational trust for his four children.
O'Donnell, 35, collapsed and died of heart failure during a match against Dundee United on 29 December.
Celtic and Motherwell sides played a sell-out charity game in O'Donnell's memory at Celtic Park in May.
Villarreal finished second in Spain's La Liga last season and can boast stars such as Turkish striker Nihat Kahveci and former Arsenal midfielder Robert Pires.
El Madrigal trio Joan Capdevila, Marcos Senna and Santi Cazorla are in the Spanish squad at Euro 2008.
"We are very pleased that Villarreal, who are an outstanding European team and a great club, accepted our invitation to play at Fir Park in this pre-season match," said Motherwell chairman John Boyle.
"It will be an emotional day for everyone associated with Motherwell as we will be renaming the main stand after Phil.
"We hope our fans will turn out in their thousands again to salute Phil and to see us play against superb opposition."
O'Donnell's brother, James, said: "It's a great honour for the main stand to be named after Phil and we appreciate deeply everything that has been done for Eileen and the children by ordinary football supporters and by the club."