Coutinho handed in a formal transfer request on Friday after the club released a statement saying he would not leave Anfield this summer.
Liverpool have already rejected two bids from the La Liga giants and Redknapp says Klopp is facing a ‘nightmare’ situation as he tries to focus on the new Premier League season.
Speaking to Sky Sports ahead of the Watford clash, he said: ‘It’s a nightmare for Liverpool and Jurgen Klopp.
‘Coming into the season, it should be a time full of optimism but instead everyone is talking about the talisman, Philippe.
‘It’s difficult now as he doesn’t want to be there – Liverpool is one of the biggest clubs in the world but he doesn’t want to be there.
‘You can sell him for £90million so what’s the best for the club? It’s getting to the stage where if he doesn’t want to be here, no player is bigger than Liverpool.
‘Take the money, he doesn’t want to stay anymore and £90m is good money, incredible money.’
Despite Coutinho informing Klopp that he wanted to leave, Liverpool legend Jamie Carragher believes the playmaker will stay.
Philippe Coutinho’s 2016/17 PL stats
‘I still think he’ll stay,’ he said. ‘Luis Suarez put in a transfer request and stayed for another 12 months and played some of the best football of his career.’
But Carragher admits Liverpool’s hopes of finishing in the top four – never mind winning the title – will be affected if Coutinho does secure a dream move to Barca.
‘It will make a massive impact on Liverpool,’ he added. ‘We can’t afford a nothing season where we don’t compete – what’s the point of Klopp being here if you’re going to sell your best players?’