Former Motherwell and PSV Eindhoven defender Mitchell van der Gaag was taken to hospital after collapsing in the dugout when managing Belenenses on the weekend.
The 41-year old Dutchman momentarily lost consciousness during his side's 1-0 win over former club Maritimo but recovered quickly after undergoing an examination from a heart specialist.
"Mitchell had low blood pressure and lost consciousness briefly," said a club statement. "He was taken to the hospital in Santa Cruz, to be re-evaluated by the cardiology team.
"He spent the night there, as a precaution, left the hospital the next morning and is now resting at home."