David Luiz maintains he will take both criticism and praise in his stride as he concentrates on just doing an \"honest\" day\'s work at the heart of the Chelsea defence. The wild-haired Brazilian centre-back has become something of a cult figure at Stamford Bridge following his £21 million move from Benfica just over a year ago. The 24-year-old has produced both solid displays as well as the odd eccentric performance. As Chelsea look to replace the disappointment of letting a 3-0 lead slip against Manchester United last weekend with a positive result at Everton, Luiz insists meeting his own work ethic is all that matters. \"I have been working in the same way as always, training at my best level,\" said Luiz, whose goal had put the Blues into a seemingly commanding position at the start of the second half before United launched a fightback to snatch a share of the points. \"Sometimes you get criticism, like I did, and recently I have been applauded for my work. As long as I can go home and lay down on my bed and have my conscience clear that I am doing an honest job, I am happy.\" Luiz also said to Chelsea\'s official website: \"The main thing is to continue working and maintaining the philosophy that the coach instructs. We have to do this, sometimes we are doing things that are great and not getting the results and sometimes we do things not so good and get the result. \"The main thing is to continue working hard and obviously we are not where we want to be at the moment, not fighting for first place, but we have to keep looking for victories and believe in ourselves until the end. \"There are games we have lost where we could have done better, but we can\'t change the past, we can only look to the future and know that we can do better and move up positions.\" Chelsea could have Frank Lampard available again this weekend, the midfielder having today returned to train with the squad for the first time since injuring his calf against Norwich on 21 January. John Obi Mikel has also resumed full training after seven weeks on the sidelines because of a hamstring problem. Full-back Ashley Cole has served a suspension, but captain John Terry (knee) remains a doubt. Owner Roman Abramovich was also understood to have again attended training today - this third recent visit to Cobham. The club, though, have already dispelled any suggestion that manager Andre Villas-Boas was coming under increased scrutiny from the owner.