Gary Cahill has told Kenedy to "grasp with both hands" his move to Newcastle United.
The Chelsea winger this week joined the club on loan until the end of the season.
Kenedy is ineligible to play in this afternoon's fourth-round FA Cup tie between the two clubs.
Chelsea captain Cahill gave his view on the 21-year-old's move in his programme column.
"Kenedy has moved to on loan to Newcastle this week, and I think it's a great move for him," said Cahill.
"It's an opportunity he needs to grasp with both hands, because, as Chelsea fans will have seen already, he has fantastic ability and natural talent, and now it's time to go out and get the games under his belt.
"If he can play regular Premier League football, that will only benefit him, so we wish him all the very best for that loan spell and look forward to his return."
Kenedy could make his United debut in Wednesday night's Premier League home game against Burnley.
“It was a player we were monitoring in August," said Benitez.
"We needed this position. He's a young player, has to improve, but knows the Premier League. A lot of positives, has energy, quality, but is still a young player.
"He's a good addition for us. He can play as wing back, left full-back or winger. This year he's been a wing back.
“Physically, he's fine and training with the team. It's just a question of match fitness."