The pair won the African Nations Cup with the Super Eagles and return to bolster the ranks at Chelsea, who claimed back-to-back wins for the first time since December with victories over Wigan and Sparta Prague and are seeking a third successive win in the FA Cup fourth-round replay with Brentford at Stamford Bridge.
"I think they will come back with more confidence, more belief and it has to be good for the team," Benitez said.
"It's important to have happy and confident players around, so it's good for the team that they won and they've brought that confidence and belief back with them.
"Both of them progressed as individuals through the tournament. Obi has more experience and you could expect good performances from him, but Victor was coming through and I could see he has been growing and improving. I am really pleased for both of them, and to be so influential is a great achievement for Victor."
Moses last featured for Chelsea on January 5 against Southampton and Mikel on Boxing Day against Norwich, but both are in line to return in the clash with npower League One Brentford.
Also available for the west London derby are David Luiz and Demba Ba, who missed the Sparta clash through suspension and being ineligible respectively.
John Terry is in line to return to the starting line-up for just a third start under Benitez following a knee injury, while Ashley Cole, who like Terry was an unused substitute on Thursday, could also start.
Benitez is happy with increased numbers to choose from.
"We have now more options that we didn't have before," he added.
"It's a great advantage if you want to give minutes to players, play with fresh legs. It can help to keep a higher tempo during the game."
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