However, Fryers believes that he and his teammates still have a good chance of reaching the quarter-finals of the competition.
"The lads know it's going to be hard going into the match, especially as it's at their place. Benfica are a great side but we have to be confident and concentrate on doing the right things so we can get back into the game," he told the club's official website.
"There always has to be belief when you go into every match, no matter what the score is from the first leg. We just have to work hard."
Tottenham have lost their last three matches in all competitions.