David O'Leary has admitted he fears a potential UEFA Cup semi-final showdown with former club Arsenal. The Leeds United manager is bracing himself for the prospect of an explosive clash on the European stage should both sides reach the last four of the tournament.

The mouth-watering possibility is on the cards as Leeds and Arsenal are in commanding positions going into tonight's second legs of the quarter-final ties.

Leeds hold a 3-0 cushion over Czech League leaders Slavia Prague ahead of the return at the Strahov Stadium, while Arsenal are 2-0 up on German side Werder Bremen.

Clearly, the last thing O'Leary is now looking for is to meet Wenger and Arsenal - the club he served for 20 years as a player in next month's semi-finals.

"I wouldn't want Arsenal over the two legs in the semi-finals because they are the strongest team and they've the experience," said O'Leary.

"If we do meet I would much rather it be in the final on a one-off basis, so if we get through this, then I hope we stay away from them in Friday's draw."

O'Leary, though, knows today's match with a team who have won all four of their European home ties this season is not a foregone conclusion.

O'Leary could be tempted to play three central defenders as Jonathan Woodgate is fit again.

O'Leary's other selection dilemma is whether to play David Hopkin or Matthew Jones in central midfield with Lee Bowyer suspended.