Uncapped Mata selected by Spain
The 20-year-old has become a fixture on the left flank of Unai Emery's Valencia side this season, having moved from the Real Madrid youth team in 2007.
He has scored seven goals in 28 Primera Liga appearances this term, and was included in coach Vicente Del Bosque's Spain squad to play Chile in a friendly last November.
Iniesta picked up a muscle injury in Barcelona's 6-0 win over Malaga on Sunday and has been ruled out for two weeks.
Del Bosque also has injury concerns over striker David Villa who is recovering from a knee problem.
"The knee is responding well to the treatment and I am confident I will be available to help the team on Saturday," Villa said at a promotional event on Tuesday.
Midfielders Xavi and David Silva have Achilles and muscle complaints respectively, while defender Gerard Pique missed Barca's game on Sunday with a fever.
European champions Spain, who top Group 5 with a maximum 12 points from four matches, play second-placed Turkey at the Bernabeu on Saturday, and four days later face them again in Istanbul.