Erling Haaland claimed Porto's Pablo Rosario grabbed his bottom during Manchester City's ill-tempered Champions League win at the Estádio do Dragão on Tuesday.
The pair were involved in a heated exchange in stoppage time of a stormy encounter which had already seen players clash in the tunnel at half-time.
The altercation came moments after the Norway striker had sealed a 2-0 victory with his second goal of the league-phase contest.
Haaland was fouled by Rosario, prompting another scuffle, and the forward was booked for his involvement. The 26-year-old, however, hinted that there had been more to the incident.
He told Norway's TV2: "I was really keen on a hat-trick and it seemed like he [Rosario] was very eager to stop me from getting it. It was a little interesting, that.
"You'll be seeing a picture where he's grabbing my bottom. It'll be interesting to see that picture."
City are waiting to hear whether tournament organisers UEFA might take any action after a series of flashpoints, the most serious of which occurred as players left the field at half-time.
Porto were angered that City's Marc Guéhi was not sent off after catching Gabri Veiga in the head with his arm as he leapt for a header late in the first half.
There was an immediate melee as Porto players argued with officials and their opponents, and tensions had not cooled by the interval.
Skirmishes continued as players left the field and there were reports of pushing and shoving in the tunnel and security staff stepping in to prevent events getting out of control.
Some footage appeared to show City captain Rúben Dias placing his hand on Porto coach Francesco Farioli's chest as they reached the tunnel.
- Porto 0-2 Man City: Erling Haaland's brace proves decisive in feisty Champions League clash - as it happened
- Enzo Maresca warns Man City players against unnecessary passes to Gianluigi Donnarumma
- 'Beast' Erling Haaland equals Sergio Agüero's Man City UCL mark
UEFA will await reports from referee Szymon Marciniak and match delegate Stephanie Ford before determining whether to initiate disciplinary proceedings. City could face a fine if action is taken.
City were good value for their victory but Farioli suggested the outcome could have been different if they had been reduced to 10 men.
He said: "The footage of the foul on Gabri Veiga is very clear and [Josko] Gvardiol should also have been shown a second yellow card. He behaved in an unsporting manner when he was already on a yellow.
"At this level, and playing against 10 men for an entire second half ... Things could have been different."
Veiga added: "He [Marciniak] is a world-class referee and I respect him, but when an opponent leads with his elbow and then there is blood, there is not much to say. We all make mistakes."
Haaland put the half-time furore aside to head City in front after 47 minutes. That prompted a strong response from Porto, who created a number of clear-cut chances before Haaland finally settled matters.
The Norwegian has now scored five goals in three games, three of them with his head, and he said extra practice with his dad Alf-Inge, the former City and Leeds midfielder, was paying off.
He said: "Over the years, I've worked a lot on my heading. I've improved it massively and it's become a strength of my game.
"Actually, two days ago I was practising headers with my dad in the garden!"
