Spurs have now lost seven Premier League games this season and five of those losses have come directly after matches in the Europa League.
Including last Thursday's 1-0 last-32 first-leg defeat to Dnipro Dnipropetrovsk, the North London club have played nine games in Europe this term.
They have only managed to win on their return to domestic action three times, drawing once, while they have been beaten by Arsenal, West Ham United, Newcastle United, Liverpool and now Norwich.
However, Sherwood does not believe that his side suffered a 'Europa League hangover' at Carrow Road.
"No, it's difficult to make an excuse like that," he told Sky Sports News.
"I think you've got to give Norwich some credit. They were very spirited. They did well and worked hard.
"It's just bitterly disappointing for us that we're coming away with nothing, and possibly never deserved it."
Spurs will play Dnipro in the second leg this week. That match will be followed by a home game against Cardiff City three days later.