The 25-year-old completed a long awaited move as he swapped Anfield for the Camp Nou.
Liverpool's owners, Fenway Sports Group (FSG) insisted that the decision would be made solely by Klopp.
Becker believes that Klopp will be affected by the transfer despite being the one who had to sanction it.
"I'm very lucky to call Jurgen a friend, he came to see me at Wimbledon – he's a big tennis fan and I'm a big Liverpool fan," said the Eurosport pundit.
"Ever since he's been at Liverpool I've been watching all of his matches.
"I'm very happy with the signing of Virgil van Dijk and I think selling Coutinho was very good business for Liverpool, sometimes you have to sell a player while he's at the top and it's a ridiculous amount of money.
"I think they only need one or two players – selling Coutinho will hurt him a little bit, but I'm sure with so much money in the bank now, he's going to find somebody to replace him or even two players."