Vitor Pereira says he has pulled out of the running to become the new Everton manager.
The Shanghai SIPG coach was high on the Toffees' list to succeed the sacked Marco Silva on a permanent basis.
Duncan Ferguson is currently in caretaker charge.
"It's an honour and I'm grateful to be considered by a club I have so much respect for but I am still coach of SIPG and SIPG is a club close to my heart," Pereira told Sky Sports News.
"It means that in this moment I'm not in a position to make any other commitments. I need time to think and plan my future by looking at the options I have."
His fellow Portuguese Silva was sacked after 18 months in charge following the 5-2 Merseyside derby defeat by Liverpool at Anfield.
Everton still plan to appoint a permanent manager as soon as they can despite beating Chelsea 3-1 on Saturday under Ferguson.
There was informal contact to gauge the extent of sacked ex-Arsenal boss Unai Emery's interest, while Bournemouth's Eddie Howe is another manager with admirers in the Everton boardroom.
Howe, however, insists he is committed to the Cherries and is unlikely to leave mid-season - while Spaniard Marcelino is another out-of-work coach looking for a route back into football after he was sacked by Valencia earlier this season.
Former Everton manager David Moyes has been discussed and Pereira's announcement could bring the Scot back into contention. Carlo Ancelotti, who was sacked by Italian side Napoli on Tuesday, is also a contender. The Italian was already on the list of candidates and Everton's hierarchy are sure to investigate his potential availability.
Pereira, 51, led Porto to back-to-back Primeira Liga titles after stepping up from his previous role as assistant manager in 2011. He was interviewed for the Everton manager's job in 2013 before Roberto Martinez was appointed as successor to Moyes.
After a brief stint in charge of Saudi side Al-Ahli, he helped Greek club Olympiakos win a league and cup double in 2015, but unsuccessful spells followed in charge of Fenerbahce and 1860 Munich.
He took over at Shanghai SIPG in December 2017 and led them to their first league title in his first season in charge.