The Tykes have conceded nine times in their last three outings in all competitions, compared to two in seven prior to that. The Reds bounced back from a 4-2 defeat at League One promotion rivals Sunderland with a win over Southend by the same scoreline in the FA Cup last Saturday. But a midweek loss to Manchester City Under-21s in the Checkatrade Trophy, when a 3-3 draw was followed by a 5-3 penalty shootout defeat, has left Stendel demanding better. 'The focus for the next games, especially for Saturday, is that we defend better,' the German said. 'We can score every game, but we need better defending. It is easier to win with one goal. 'We said before the start of the season that we wanted to change the defending. 'We are a very good team, we played well most of the time, I think we are one of the best teams in the league, but it is not enough. 'We want to be the best team and successful team in the league. At the moment, we are not. We need to change in the future. I hope our players understand that.' Barnsley continue their promotion drive with a trip to 10th-placed Wycombe on Saturday. Their backline will be tested further at Adams Park by the imposing Adebayo Akinfenwa, a much-travelled English Football League striker who is well renowned for his size and strength. Akinfenwa has only managed five goals in 19 appearances this season after leading Wycombe to promotion, but Stendel is well aware of the 36-year-old's threat. 'I have watched in preparation for the Wycombe game clips of Akinfenwa,' he said. 'When he has the ball he is a very good player. We need to make sure he doesn't get the ball. It is a big point for a successful game at Wycombe. "He is a good player, but he is not the best player in the league. We are prepared for him.  'We only focus on our game, our strengths, that is the important for me.' On Gareth Ainsworth's side, Stendel added: 'They play very simple, not bad, very simple. They defend good and play easy to attack and score, with less passes.' Barnsley are without the suspended Dimitri Cavare for the Wycombe clash, while Kenny Dougall, Ryan Hedges and Lloyd Isgrove are still unavailable due to injury.