Arsenal manager Mikel Arteta has admitted that his team are "lacking ruthlessness" amid their recent dip in form.
The Gunners appeared to have turned their fortunes around at the start of the year, but back-to-back defeats to Wolverhampton Wanderers and Aston Villa has seen them slip to 11th in the Premier League table.
Arteta has already admitted that his side - who sit nine points adrift of the Champions League places - are not realistically capable of challenging for the top four, and the Spaniard has urged his side to find their ruthless streak again.
Speaking to Sky Sports News, Arteta said: "We are lacking ruthlessness, at the moment, because we gave a goal away, and we gave another two big chances away ourselves against Villa.
"We gave the game away against Wolves. We had the chances to put the game to bed and even when you make a mistake you have to try and correct it and be ruthless in the opponent's box, and we didn't do that either.
"So then you're not going to win football matches. Leeds are a really brave, dynamic and energetic team that goes for the three points all the time - constantly attacking, constantly a threat, constantly pressing.
"First you have to match and improve their energy levels, and then you have to play your game and try to take it where we want and not where they want. If you do that you have a good chance to win."
Leeds United sit one point and one place ahead of Arsenal - who have played a game more - before Sunday afternoon's showdown at the Emirates Stadium.
