The successful coach has explained his decision to exclude the former Valencia man from his list, while Bayern Munich contacted him with the request to exclude Javi Martinez
Mata featured at Euro 2012 with the Spanish national side before travelling to London to take part in the summer Olympics, and Del Bosque feels omitting the 24-year-old was the right thing to do given the circumstances.
"Mata's absence may be conspicuous but there is an explanation. Chelsea rang us to request that we do not call him up because he has hardly had any time off this summer," Del Bosque stated at a press conference.
"We obviously have a duty to do what's best for our squad, but there are situations like this that just make common sense."
The Spain boss then went on to say that Bayern Munich head coach Jupp Heynckes also contacted him with the request not to call up Javi Martinez.
"Javi Martinez wouldn't have come with us anyway but yes, I have to say that Heynckes called me with concerns about the length of time he has not played for and the difficulty of getting used to German football. While there is no league competition, this time will be very useful for just that."
The reigning European and world champions first take on Saudi Arabia before starting their 2014 World Cup qualifying campaign against Georgia on September 10.