Arsenal have made an offer for Chelsea's unsettled French defender William Gallas, manager Arsene Wenger has confirmed.

Wenger confirmed the bid today as he left the door open for defender Ashley Cole to join Chelsea by leaving him out of their Champions League squad to play Dinamo Zagreb tomorrow.

Negotiations between the Premier League rivals over England leftback Cole, the subject of a reported £16.5 million offer from the champions, appeared to have broken down.

Wenger predicted it was "50-50" if Cole stayed at Arsenal.

"We are still in no man's land surrounding his (Cole) move. I made an offer for William Gallas and that is how far we are," Wenger told a news conference.

The offer is believed to be in the region of £5 million.

Cole did not play in Arsenal's league opener against Aston Villa on Saturday, despite making himself available.

"I will not play Ashley because the transfer possibility is not closed and if he plays for us then he might move to another club who is in the Champions League and will not be able to play for them," added Wenger.

"I am very keen to resolve this because we are at the beginning of the season and you want your squad to be settled. We still have a rapport with Ashley Cole and just because there is a chance of a transfer doesn't mean we are not talking to him anymore."

Goalkeeper Jens Lehmann will also be missing tomorrow night.

The German - who was suspended from the first leg following his red card in last season's European Cup final - has a slight knee problem.

Summer signing Tomas Rosicky and winger Jose Antonio Reyes, linked with Real Madrid, are unavailable (both groin).

Wenger must also decide whether to rest captain Thierry Henry, who has been struggling for full match fitness after his World Cup exploits with France.

Theo Walcott came off the bench to make his debut in Saturday's Barclays Premiership clash with Aston Villa and could feature tomorrow.

Gael Clichy (foot), Philippe Senderos (shoulder), Abou Diaby (ankle) and Lauren (knee) are all longer-term absentees.

Provisional squad: Almunia, Hoyte, Eboue, Toure, Djourou, Fabregas, Gilberto, Ljungberg, Hleb, Van Persie, Adebayor, Poom, Henry, Walcott, Flamini, Aliadiere, Cygan, Traore, Song.  Agencies