Neil Lennon says he feels no pressure to progress in the Europa League There is a thin line between success and failure and Celtic head into tonight's game with Sion walking along that line. Neil Lennon insists he is under no pressure from the boardroom to make it into the group stages of the Europa League. The second leg is a winner takes all situation as the first leg ended goalless. The players will still have Lennon's views on how they performed against St Johnstone at the weekend fresh in their minds and will not want to have another blast from the manager later tonight. Lennon's first attempt as manager in Europe last season saw Celtic knocked out of the Champions League and Europa League at the qualifying stages. The recently published financial results showed just how important playing in Europe is to a club the size of Celtic.In the media room at the Stade de Tourbillon ahead of tonight's second leg, Lennon was asked if there was pressure to go through and replied: "Certainly not from up above, no, not at all. The pressure is no different from any other game for Celtic, every game is a huge game, there is always something riding on it. It is a very important game for me personally. I would dearly love to take the club into the group stages. It is going to be very difficult. Sion are a good team, which they proved last week. And in the context of the season it is a big game because it would open doors revenue-wise and it would keep our interest in Europe going at least until December. For the players as well, it is important to get into the group stages where they can develop their game a bit more." Asked if an early European exit would hamper his attempts to add to his squad before the closure of the transfer window Lennon said: "I wouldn't have thought so. We have been working away in the background for the last couple of weeks so hopefully after tomorrow night we can move on with that."After Celtic lost to St Johnstone Lennon castigated his players, describing their performance as "immature" and "complacent". Asked if he had any regrets about what could be considered harsh criticism, the former Celtic captain replied: "No. Not all. I didn't think it was harsh. It was the way I saw it. I am pretty good with the players when they perform well and if they don't perform the way we expect them to I have every right in pointing that out. I can't pull the wool over people's eyes and I am not prepared to do that. We had a meeting on Monday. We analysed the game and we closed the door on that and moved on. They are a lot better today. There were a few things that cleared the air but it was no different from any other meeting we've had after a poor result. The performance in general was okay. We didn't take our chances but the overall performance was okay. We just need to put our chances away. Goals change games and the psychology of games. The cutting edge has been lacking in the last two games but I've no worries that it won't come back soon. They have looked brighter in training. We are obviously disappointed with the result and on the back of two goalless games at home we are looking for a wee bit of positivity in the final third."Ahead of tonight's game there are doubts over the fitness of Kelvin Wilson (leg), Beram Kayal and Gary Hooper (both ankle), who all missed the last two game, while Charlie Mulgrew is battling to recover from a hamstring complaint picked up in the defeat by St Johnstone. Wilson, Kayal and Hooper have resumed training but a decision on whether or not they will be fit enough to start against Sion will be left until nearer kick-off. Lennon said: "I think all three are doubtful. We put them through a light session yesterday and will do it again tonight. We brought them with us but there is no guarantee they will play tomorrow night. Gamble? It will depend on the advice of the medical team. But if it does long-term damage then no. Even if we don't get one or two players back we will still have a squad strong enough to have a go tomorrow night."