The 26-year-old from Bilbao had two of his teeth knocked out when he was set upon by a group of youths in the street.
It is believed he was attacked as he walked to a nightclub in the town.
He took part in Saturday’s live show despite being exiting the competition in the second round of the series.
The Spanish dancer had partnered EastEnders actress Tameka Empson, and is due to undergo dental surgery on Monday.
However, he is expected to rejoin rehearsals later in the week.
A BBC spokesman said: “Gorka was sadly the victim of an unprovoked incident in Blackpool on Saturday night, but he will be back in training this week and is looking forward to the group routine next weekend.”
The Sun reported Gorka was with fellow professional dancers Aljaz Skorjanec and Neil Jones when he was assaulted.
The paper said they had been walking to the Flamingo nightclub near Blackpool Tower when a group of youths approached them.
It added that Marquez had not been drinking and had not made any contact with the gang before the assault, which was not reported to police.