Chelsea midfielder John Obi Mikel believes fan negativity is affecting the players at the Premier League club.Interim manager Rafael Benitez has come in for a barrage of criticism from Chelsea supporters since he was parachuted into the manager's job following the sacking of terrace favourite Roberto Di Matteo in November, prompting angry words from the Spaniard himself last month."Sometimes it doesn't help when the fans are not happy. When you give the ball away there is pressure," midfielder Mikel was quoted as saying on the Evening Standard's website (www.standard.co.uk) on Monday."This is our job. Fans come to watch the football and we have a responsibility to pay them back and make sure we play well. Every game we try to do that, sometimes it works, sometimes it doesn't."I have been here for seven years and they (the fans) are fantastic and have always supported us until the end. I hope that continues throughout the season," the Nigerian added."This is when we need them the most. Let's hope we can all go through the rest of the season together. Chelsea fans have always been great and I know they will continue to be great with the players."Benitez issued a fiery plea at the end of last month for fans to get behind the team and end the abuse aimed in his direction, but the doubters were in loud voice when Chelsea went 2-0 down to Manchester United in the FA Cup on Sunday.Benitez, however, had the last laugh as his side fought back to draw 2-2 at Old Trafford and force a quarterfinal replay.