BERLIN, Jan 4 (Reuters) - Borussia Dortmund have held talks with unsettled Arsenal goalkeeper Jens Lehmann and were 'cautiously optimistic' he would accept an offer to return to his former club, the Bundesliga side's managing director said.'In my view it was a very positive chat. Jens said he would think about (the offer), but also asked that he not be put under pressure to make a decision, which is fine by us,' managing director Hans-Joachim Watzke told a news conference.'I don't know when a decision will come... but I can say that we are cautiously optimistic about both the talks and the decision.'But Arsenal manager Arsene Wenger poured cold water on the prospect of Lehmann returning home, saying he remained firmly part of the Premier League club's plans.'I know nothing about it, so it would have surprised me if a player who was under contract was announced somewhere else today,' Wenger told reporters on Friday.'That would have been a big surprise to me. As far as I am concerned, Jens Lehmann will be in goal at Burnley (in the FA Cup on Sunday). He is playing at Burnley.'Germany's first choice keeper at the 2006 World Cup, Lehmann is keen to keep his place in the national team for the European Championship finals in Switzerland and Austria in June.But this season he has made only two league appearances and played in two European ties for Arsenal.Wenger said last month that Lehmann might be allowed to leave the club in January if they received the right offer.'The door is not closed,' Wenger added. 'The opportunity, for Jens to leave, if he is convinced he has to play in the European Championship, is the only one.'So, if he wants to play somewhere else, the door is not completely closed, but he still plays for us at Burnley. I am 99.9 per cent sure of that.'Lehmann joined Arsenal from Dortmund in 2003. • Serbia right back Antonio Rukavina has joined German Bundesliga side Borussia Dortmund from Partizan Belgrade, the Serbian fisrt division leaders said on their website. 'Rukavina has signed a 4-1/2-year contract with Borussia Dortmund after passing a medical on Friday and we are sorry to see our captain leave after only 12 months with us,' the club said. The 23-year old has made seven international appearances and scored three goals in 45 matches for Partizan after joining them from neighbours Bezanija.