Porto's Liga match against Estoril was suspended on Monday for safety reasons amid fears a stand would collapse.
The clubs were playing at Estoril's Estadio Antonio Coimbra da Mot where security forced instructed supporters to leave the away stand after damage to the foundation began appearing.
The match, in which Porto was losing 1-0, was then called at half-time, with a restart date yet to be set.
A statement on the Estoril website read: "After meeting the entities of Estoril Praia, FC Porto, Liga Portugal and Security Forces, it was understood that the security conditions were not met for the game to continue.
"The interruption is linked to the fact that part of the north side of the Estadio Antonio Coimbra da Mota had damage in the middle, which caused some alarm and that led the authorities to safely evacuate the entire stand in question.
"In due time, the fans who have come to watch the game will be informed about how they will be compensated for the tickets they acquired."
Porto's website posted a statement of its own, confirming the match had yet to be rescheduled.
"The match Estoril-FCP [Porto], scheduled for this Monday evening, for matchday 18 of Liga NOS, has been suspended at halftime, for safety reasons," the message read.
"No date to resume the match has been set, as the decisions will have to be reached by agreement between both clubs - out of the table is the chance to play it on Tuesday, January 16."