Questions were initially risen when the 23-year-old attacking midfielder was a no-show at Mexico's first practice session as they prepare for the Olympics.
"He told us which team [he's signing for], but I'm not at liberty to say which," said Tena to reporters in Mexico City. "For us, it's much better that he's calm, for him to fix his contractual situation and come back, if not in his best physical form, certainly much better mentally now that he knows where he's going to play."
After spending much of his youth at Barcelona, dos Santos was expected to make a splash with Spurs when he signed in June 2008, but the marriage never worked out.
Over the past four years, dos Santos has only made 14 starts for Tottenham—scoring just three goals.
With him heading over to London to do some paperwork, it's speculated that the Mexican attacker will have a new club by the end of the weekend.
While dos Santos would certainly garner playing time for Atletico, issues may arise considering their packed midfield—which includes Tiago and Diego.