Spain call up Malaga's Monreal
Monreal, 25, who has won four caps for the world and European champions, will join the rest of the squad on Monday, Malaga said on their website.
Real Madrid defender Ramos had to be substituted in the first half of Saturday's friendly against Tianjin Teda at the end of their tour of China.
Ramos injured his back while Jose Mourinho's team were on tour in the United States and has missed a large part of the pre-season. He is in doubt for next weekend's Spanish Super Cup first leg against Barcelona.