Liga leaders Barca spent most of the last transfer window trying to lure Coutinho to Catalonia but their attempts were in vain, with sporting director Robert Fernandez saying Liverpool demanded 200 million euros (£177.23 million) for the player.
Speaking at a news conference ahead of Liverpool's Champions League Group E game at Sevilla, Klopp said he was unmoved by new media reports in Spain stating that Barcelona will make a fresh approach for Coutinho in the January transfer window.
"I'm not worried about it. The only opportunity for us to be successful is to have good players in the team. It is our job to make sure these players want to stay at Liverpool and don't want to go somewhere else," the German coach said.
"If players still want to go somewhere else they can have different reasons, but it is not my problem in this moment because it is a long season to go. We have this team together now and we want to be as successful as possible."
Coutinho did not play until a month into the Premier League season after all the speculation but is back on top form. He has scored five goals, including one in Saturday's 3-0 home win over Southampton, and provided four assists in his last seven games.
"Phil is 100 percent at Liverpool. After all the talks it's possible not only for him but all the other players (to leave). When the market is open there are discussions and when the market closes we're all professionals and do the job again," Klopp added.
FANOUS ATMOSPHERE
The winners of Tuesday's game at Sevilla's atmospheric Sanchez Pizjuan stadium will seal a place in the last 16 of the Champions League, a feat Liverpool have not achieved since 2009 when Rafael Benitez was in charge.
The Merseysiders will also be guaranteed top spot in Group E if they beat Sevilla at the third time of asking.
Klopp's side lost the 2016 Europa League final to the Spaniards and drew 2-2 with them at Anfield in September due to a late equaliser by Sevilla's Joaquin Correa.
"In the group stage you cannot choose where you get the points. The closer you get to the end the more decisive the games are. Everybody knows if we hadn't conceded that goal the situation would be even better," Klopp added.
"I played twice here with Mainz and (Borussia) Dortmund. This is a really famous atmosphere. It is always good but it depends on the performance of the away team. It is our job to make the game not so enjoyable."
Sevilla are missing captain Nico Pareja and fellow defenders Martin Montoya and Daniel Carrico through injury, while Klopp has a full squad to choose from except for defender Nathaniel Clyne, who has been out all season with a back problem.
(Reporting by Richard Martin in Barcelona; editing by Ken Ferris)
