Bundesliga strugglers Borussia Dortmund have agreed to sign Slovenia international Kevin Kampl in January.
Cardiff have agreed to sell Norwegian midfielder Mats Daehli to Freiburg in January.
Defenders Titus Bramble and Matt Kilgallon are in the final months of their current agreements, and Bramble has consistently said he would like to stay.
The centre-half is back in favour and has started 10 games in succession, but with Sunderland in a fight for Premier League survival his future will remain unclear until the summer.
O'Neill told the Sunderland Echo: "Now, at this minute, the most important issue is trying to get points on the board. I know it's a cliche, but those things can wait."
Sunderland have taken just two points from a possible 18 and go into this weekend's game against Norwich just six points above the bottom three.
O'Neill's side face a daunting run of fixtures post-Norwich as they take on Manchester United, Chelsea and Everton either side of a derby at Newcastle.