Amid stiff competition for places, there was no call-up for Swansea City midfielder Michu as Del Bosque said he preferred not to experiment too much with key World Cup qualifiers against France and Finland looming at the end of next month.
Barcelona captain Carles Puyol returns to the squad after missing Euro 2012 through injury and will make his 100th appearance if he features against the South American champions on Wednesday.
"I know it's a friendly and we could have experimented more but we have two extremely tough games in March," Del Bosque told a news conference at the Spanish football federation (RFEF) headquarters outside Madrid.
"We have to treat it as a preparation for those and it's going to be a difficult game," he added.
"We were left with something of a bad taste in our mouths having to leave out some players who deserve to be with us."
Isco, 20, was voted by coaches the 'revelation' of La Liga last season and he won the 'Golden Boy' trophy as the best Under-21 player in Europe.
He was called into Del Bosque's provisional squad for Euro 2012 and has been a leading light as Malaga have impressed in their debut Champions League campaign.
