The pair lay on the pitch at one of Red Bull New York's training facilities during the opening session for Luis de la Fuente's side.
The Spanish football federation (RFEF) told Reuters that both players are expected to be available for Sunday's match and that their separate work was a precautionary measure as part of workload management.
De la Fuente said after Spain's semi-final win over France that Porro had been carrying a knock. Reuters understands the full back has suffered a hamstring strain, although the problem is not considered serious.
Lamine's situation appears less concerning. De la Fuente said after the France match that the teenager had "nothing", but the physical effects of his duel with Lucas Digne and Theo Hernandez were visible the following day, with the forward nursing aches and bruises from a demanding match.
Spain's priority is to ensure Yamal, Porro and the rest of the squad are as fresh as possible for the final.
For the rest of the squad, the 15 minutes of training open to the media passed without incident, with the players relaxed and upbeat despite humid conditions and temperatures of around 30 degrees Celsius (86 degrees Fahrenheit).
Spain have three days to adjust to the heat and humidity before playing only their second outdoor match of the tournament.