Tel was introduced in the 63rd minute in place of Dominic Solanke but was unable to change the course of the match, with Tottenham managing just two shots on target as their goalless run in the Premier League stretched beyond 400 minutes.
Cameras caught De Zerbi approaching the French forward at the final whistle, gesturing animatedly as he appeared to explain something before walking away abruptly, a moment that quickly drew attention on social media given the head coach's evident frustration.
Speaking afterwards, De Zerbi confirmed the exchange had been a tactical coaching point rather than any kind of dressing-down, explaining he had wanted Tel to adjust his body positioning in the false nine role he had been asked to play.
"The body shape. He is a striker and the striker can play with the shoulder on the goal," De Zerbi said. "If we are playing with Maddison, Kudus and Savio, he has to play as a striker and the striker has to look at the goal or the cross from Robertson. He has to stay inside because he started as a striker eh?
"Now he is playing as a winger but he started his career as a striker, but I love Mathys as a player, as a guy and there is not a problem."
The exchange came at the end of a fourth successive league match without a goal for Tottenham, a run that has left the club level on points with the bottom three and prompted boos from home supporters inside the Tottenham Hotspur Stadium at full time. It marks the first time in the club's history that Spurs have failed to score in each of their opening four league matches of a season.
De Zerbi has repeatedly pointed to a disrupted pre-season, hampered by World Cup call-ups and a string of injuries to key attacking players, as the underlying cause of his side's struggles in front of goal, while insisting there is no lasting issue between himself and Tel, who arrived at the club over the summer as one of several attacking reinforcements yet to make an impact.