Ducker noted it's not been confirmed whether the matter has been reported to police. Sterling went on to score twice in the win.
CCTV footage of the incident reportedly exists, and the attacker was not someone known to the 23-year-old.
Sterling was a frequent target of media criticism leading up to his 2015 move from Liverpool to Manchester City.
In an interview with Natalie Pirks of BBC Sport, he explained why he turned down a significant offer from the Reds in 2015 and how he wasn't the "money-grabbing 20-year-old" he was being portrayed as.
While he initially struggled with the Sky Blues, Sterling has been excellent in the 2017-18 campaign. He leads a red-hot City squad in scoring and has been one of the most important players behind the team's record-breaking Premier League unbeaten run of 16 games.
Manager Pep Guardiola didn't mention the alleged abuse after the match, and the club has yet to respond to the report.