Coutinho, 24, signed a five-year deal with the Premier League club in January, but speculation of a possible move to Barca persists.
But Klopp is remaining calm over the Brazilian's future, saying no player he wanted to retain would be let go in the off-season.
"When did he sign his new contract? So that would be a nice idea," the German told UK newspapers, before jokingly adding: "With a £400million clause."
Klopp continued: "There are absolutely no plans. What our owners say is there is the absolute opportunity not to sell anybody if we do not want to.
"That means we can bring in others players and it is a good situation.
"We have a stable squad with a good basis. We want to bring a few in with fresh blood but nobody will leave us without our say, so I am completely relaxed about this."
Coutinho has 10 goals and six assists in 29 Premier League games this season, helping Liverpool into third in the table.
Klopp's men face West Ham and Middlesbrough to finish the campaign as they eye a top-four finish.