Goal reported on Wednesday that the two players are set to switch clubs, with the Serie A side hopeful of agreeing personal terms with the striker soon.
Taider is a box-to-box central midfielder who went to the World Cup finals with Algeria and played two games in Brazil, while Koeman is also willing to take 34-year-old defender Hugo Campagnaro as part of any deal.
"We are looking for the best for Osvaldo and the best for the club," Koeman told BBC Radio Solent.
"Taider brings quality and we need that. We need competition in the squad as well and that will be good."
The Dutchman stated that Southampton are closing in on three new signings after losing Rickie Lambert, Luke Shaw, Adam Lallana, Dejan Lovren and Calum Chambers.
"We hope to do that this weekend and then we have two weeks still to prepare for the Liverpool game," said the former Netherlands defender.