William Gallas: I have changed the mentality at Tottenham William Gallas says he has tried to instill a winning mentality during his time at Tottenham. The French defender, who was hoping to start tonight's Europa League fixture against Lyon at White Hart Lane, is out of contract in the summer and unlikely to be offered a new deal. However, the 35-year-old will be able to leave the club knowing he has helped to create a hard edge they have sometimes lacked at the club. "Maybe I have tried [to change the mentality]," said Gallas. I played for Chelsea from 2001 until 2006 and I won some [three] trophies there, so I know what you have to do. The players here have the right mentality now because they want to win every game. If we draw a match, some of my team-mates can be very upset but that is a good thing. Two years ago, those same players were not thinking like that. Even if we don't play well, we have to take the three points and maybe some people didn't understand my reaction [to poor results]. Now, though, the attitude of some players has changed and that is a positive thing. Tonight's Europa League meeting is one of the most enticing of the round, yet this competition is not where Tottenham want to be. If they finish in the Premier League's top four, Andre Villas-Boas's team should reach the Champions League. Although Gallas might not be around to share the adventure, he feels his forthright, at times confrontational, approach to speaking to team-mates has instilled a steeliness that was lacking in previous campaigns. Gallas" English career has certainly been eventful. His displays on the pitch have mostly been strong but there have also been moments of controversy. Acrimony preceded his move from Chelsea to Arsenal in 2006 and, while with the Gunners, he lost the captaincy in November 2008 following criticism of the team in an interview. There had also been a petulant reaction to a late equaliser conceded in a game at Birmingham in February that year. Those who support Gallas say such behaviour comes only from a fierce desire to win and he pinpointed where his current club must do better. "Tottenham can improve against the smaller teams," he said. When we play those sides, we have to take points and we're starting to do it. The important thing for everyone is to chase perfection. Even if you win a game, some things are not right, so you have to correct them. That means that in training you have to speak with the players and say what is good and what is bad. If you do this, you will get what you want. If Gallas departs, it will be interesting to see which other players take on this responsibility. Spurs" squad is relatively young, with only four players - Gallas, Scott Parker, Jermain Defoe and Brad Friedel - over 30, although Clint Dempsey reaches the milestone next month. If every player were fit, Spurs" first-choice starting XI could have an average age of less than 25. Matches like tonight's, against the team second in France's Ligue 1 will test their mettle and provide valuable experience if Champions League qualification is secured. Villas-Boas took Porto to the Europa League title in 2011 but his experience in the main competition has been far less enjoyable. In his next job, at Chelsea, his team were beaten 3-1 at Napoli in the first leg of their last-16 tie and Villas-Boas was sacked before the return game. The Portuguese believes Spurs" performance against Lyon will show whether his squad are ready for the Champions League. "Lyon have tremendous Champions League experience," he said. These games are a learning experience and they can serve that purpose towards the future. I called it when the draw came out - this is like a Champions League tie. Lyon have stumbled in their last two matches, suffering 3-1 defeats at Ajaccio and at home against Lille. Lisandro Lopez could have joined Spurs on a short-term deal in the closing hours of the January transfer window only for Lyon to hang on to the striker. Former Spurs midfielder Steed Malbranque will be a familiar face tonight, while the French club's coach, Remi Garde, was signed by Arsenal manager Arsene Wenger in August 1996.