Barcelona were linked with moves for Wijnaldum and Garcia in the recently closed summer transfer window, and they could return for them in January.
With Garcia's contract with Manchester City set to expire in the summer, Barca would be hoping they can get him for a cut-price deal in January.
Similarly, Wijnaldum's current contract with Liverpool will also run out in the next summer, and Barca might look to capitalise on the situation and sign the player, who Koeman recently admitted he wanted to bring to the club in the summer.
Meanwhile, Barcelona conceded their first defeat under Koeman as they were beaten by Getafe 1-0 in their recent LaLiga fixture. A victory in the game would have helped Barca go top of the table, but Jaime Mata's goal from the spot in the 56th minute took three points away from the Catalans.