Nuno Espirito Santo has revealed three absentees for Tottenham Hotspur’s Europa Conference League clash with Rennes – and he is not yet sure if they will make it back in time to face Chelsea.Tottenham get their Conference League group campaign up and running on Thursday against Rennes. It should be a tough match at this stage of the competition – and especially given that there is another tough test in the Premier League on the horizon.Just three days after the Rennes game, Spurs will contest a London derby with Chelsea, meaning Nuno has to juggle the situation somewhat.What makes matters harder for him is the fact that he will be without Son Heung-min, Eric Dier and Ryan Sessegnon for at least the first of those two challenges.He said: “I can tell you the players that did not travel. Son did not travel, Dier did not travel and Sessegnon did not travel. That’s the team news.”Asked if they could return against Chelsea, he added: “I cannot say. They are improving, day by day they are better, but alongside the South American players, we still have to assess.”There is more positive news for Steven Bergwijn, though, who is able to return after an injury he picked up on international duty.Nuno confirmed: “Bergwijn is better. He travelled with us, he trained yesterday and today, he is much better.”If available to play a major role, some of the onus may be on Bergwijn to help Tottenham in the final third – especially with Son out.Spurs are yet to score more than one goal in any of their four Premier League matches this season, beginning with three 1-0 wins before the weekend’s 3-0 loss to Crystal Palace.Clearly, they need to rediscover their spark in front of goal – and Nuno says they are hard at work doing so.On how they are addressing the issue of creativity, he said: “Training, training, spending as much time as we can on the training ground. Preparing the players, trying to find solutions and then give them the support and the confidence to compete and try to improve their performances.“I don’t know any other recipes for success. It’s hard work. Hard work and the boys are doing it.“They are realising that in football there are ups and downs and what’s important is how you react to it.”Switching the focus to the opposition, Nuno is aware of how much of a threat Rennes could pose.He said of the French side: “Tough team. We had a chance to see them, and now were going to prepare the meeting and pass on all the details we can to the players.“But we expect a tough match. Theyre a good team.”Rennes came third in Ligue 1 last season, a year in which they also featured in the Champions League.Asked how their European experience may affect things, Nuno replied: “We looked at Rennes and analyse them as a team from the previous game and the game before.“We know we are going to find a tough match, a tough team, one that is very aggressive on the pressing, playing at home, we know it is going to be harder.“We also have a lot of experience in Europe. The past doesn’t mean big things now, this is the present and we have to deal with the situation now and Rennes represent a tough, tough challenge for us and we have to raise up our standards.”Subscribe for free to TEAMtalk’s daily newsletter…While Nuno brushed off talk of the past, he also wasn’t willing to look too far ahead, denying the upcoming Chelsea game would be on his mind.He said: “We focus on our own game. We focus on tomorrow, and we are ready. Were prepared.“Its game by game. Each thing at a time. We have to focus on our match [today].”READ MORE: Barcelona plot transfer havoc for star Tottenham have only just signed