The Spain manager, at Goodison Park to run the rule over Swansea's quartet of Spaniards, saw two sides cancel each other out in a tight Barclays Premier League battle.
The in-form Michu went the closest of two hard-working sides to scoring when he forced Tim Howard to tip a shot onto the crossbar in the first half.
Everton had the better of the second period but Flores and partner Ashley Williams were solid and while Marouane Fellaini forced a late save from Michel Vorm, referee Phil Dowd had spotted an infringement.
Everton started strongly with early chances for Fellaini and Nikica Jelavic while Pablo Hernandez, another of the four Swansea Spaniards hoping to impress De Bosque, Angel Rangel being the other, screwed an ambitious effort well wide.
Victor Anichebe went close when he reacted quickly after Fellaini headed on a Phil Jagielka ball but Vorm palmed away his header and Williams hacked off the line.
Michu was inches away from giving Swansea the lead as he raced onto a fine ball from Nathan Dyer and delicately attempted to chip Howard from close range, but the goalkeeper was able to palm it over.
Fellaini shot tamely at Vorm and Leon Osman, looking to mark the 10th anniversary of his debut with a goal, headed a glorious chance wide.
Everton kept the pressure up early in the second half but did little to seriously concern Vorm, and then had a penalty claim waved away when Jelavic went down in a challenge from Williams.
Jagielka headed a fine chance over before Fellaini broke through on goal, only to be penalised for a push.