Southampton have been linked with a Â£16million January move for the 22-year-old, currently on loan at Rennes.
Arsenal are also said to be tracking the Colombia star, but Koeman ruled out chasing any midfield recruits in the January window.
"We don't need midfielders, so no," said Koeman, when asked if Quintero is a target.
"I'm very happy with the players we have.
"I can't say it's 100 per cent because it's football, but it's unlikely that we'll have new players in January.
"It's an important line in your team, to have good ball possession.
"And I'm happy with the balance there in our squad.
"It's always the most difficult decision, who plays in midfield."
Ryan Bertrand has won a recall to the England squad for upcoming friendlies against Spain and France, with Koeman hailing the ex-Chelsea star as the Premier League's top left-back.
Bertrand only recovered from knee surgery at the end of September, with Koeman praising his quick return to top form.
"Maybe I was a little surprised after the time he was out of football," said Koeman.
"And it was a fast goal for the player to make the national team, but it's a well-deserved goal because he's playing very, very well.
"In my opinion he's the best in the Premier League in that position."
Southampton face Sunderland at the Stadium of Light in Premier League action on Saturday, but must do without banned midfielder Victor Wanyama.
Shane Long had closed in on a return after ankle trouble, but suffered a minor reaction in training on Wednesday and will now miss the Wearside trip.
"Nobody is coming back," said Koeman.
"Shane and Jay (Rodriguez) are still out
Shane was close.
"He trained yesterday with the team but he's still not 100 per cent.
"So it's the same players, maybe the same team but without Wanyama.
"Victor's a miss because he's always starting normally, a key player, and that means that he's important for the team, in his defending from the midfield position."
Southampton can extend their best-ever start to a Premier League season in terms of away fixtures this weekend, as Koeman's men are chasing a sixth straight league match without defeat on the road.
Koeman continues to prize points ahead of unbeaten runs however.
The Saints have only won one in 12 on the road, a contrasting statistic the Dutch boss hopes his side can quickly improve
"If you don't lose away that gives everybody a good feeling," said Koeman.
"The feeling to be unbeaten until now, it's a good feeling.
"But if you count points maybe it's better to lose one and to win one.
"It was a long time ago that we won away, against Chelsea, and it's not always the performance that we expect of the team in our away games.
"Maybe that confidence can change this weekend, because we need a win."
Source : PA