"We have to protect the player and the best thing for him to do is to rest at home," he said.
"He has been under pressure this week and so it's important we do the right thing. I'm sorry for the fans that he can't come.
"He will keep working at home and join up with us again when we return next week.
"He's the captain of our team. He is a key player and I'm sure our fans over here will enjoy his goals during the season.
"We still have a lot of big names who will be involved on Sunday. Torres, Reina, Alonso and Mascherano are all here and so there will be plenty of quality for the Singapore fans to enjoy."