The Newcastle United winger could be retrospectively punished with a three-game ban for an off-the-ball kick at Cardiff City’s Victor Camarasa on Saturday.
Kenedy also had an injury-time penalty saved by Neil Etheridge at the Cardiff City Stadium, and the game ended goalless.
Cardiff manager Neil Warnock labelled the save as “poetic justice” given than referee Craig Pawson seemingly missed Kenedy’s kick at Camarasa.
Benitez can ill-afford to lose loanee Kenedy, already ineligible to play in Sunday’s game against Chelsea, for three games.
“It will not be good (if he’s banned), but it’s important that he stays focused,” said United’s manager.
“It’s a time when we know everything has changed since last season. We have a lot of players who are the same players as last season, and we need to make sure we start playing at the same level we played at before towards the end of last season.
“We have new additions. We have increased the competition, and what we need to make sure is that every player is focused and ready to give everything for the team. They have to keep pushing every game.”
Asked if Kenedy listens to advice, Benitez said: “Yes, he listens to advice. This group of players, they’re quite good in the training sessions.
“They are keen to do and learn things. Sometimes they can do them, sometimes they cannot, but we have to keep working.”
Benitez added: “I think all of us will learn from this game.”
Warnock felt that Kenedy should have been dismissed for the kick.
“Sometimes you don’t get what you deserve,” said Warnock. “The lad Kenedy shouldn’t have been on the pitch. It was a straight red.”
Pawson pointed to the spot after Sean Morrison handled in the area in the 95th minute.
“Regarding the penalty, Morrison’s hand is outside the box and his body is inside. I thought it was poetic justice,” said Warnock.
Benitez said: “There were too many decisions I didn’t like during the game. Some went in our favour, some went against us.”