Adebayor returned to action following a three-match suspension to help Spurs earn a 3-1 win over Panathinaikos on Thursday night, while Defoe also found the net.
Tottenham won seven of the eight games the duo started together last season - although Harry Redknapp largely preferred to play Rafael van der Vaart behind a lone front man.
Although Andre Villas-Boas started with a lone front-man system, he has now switched to Adebayor and Defoe playing together up front in a 4-4-2 system.
When asked whether the partnership was up there with the best in the Premier League, Friedel said: "Absolutely. When we have played with two up front, Jermain has really thrived on it, as he can save his energy for when he is inside the box. That is when it really matters for us.
"Last season the system we played was slightly different, with Rafael van der Vaart just behind a lone forward, while at the beginning of this year injuries meant we didn't have the chance to play with two up front, especially at home.
"Jermain always plays on the shoulder of the defender so if a team want to push high up the pitch, he will always keep them honest.
"The goal he scored against Panathinaikos was just onside but he is always right on the edge so defenders have to keep an eye on him."
Last year Redknapp described the Europa League as a "punishment", but Villas-Boas is determined to lift the cup that he won in 2010 with Porto.
"Unlike last year, it's clear that the manager wants to win it," Friedel said.
"You can tell that by team selection. Every time we put a very strong team on the pitch and he has not mixed his words at all.
"He wants to try to win the competition. So we are going to take it very seriously."
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