Chelsea's Cole Palmer has been ruled out for the Blues' key clash against Brighton this evening.The English midfielder is one of several players out this evening, including Brazilian Joao Pedro, who did not feature in Chelsea's last game.Palmer, who played in Chelsea's recent defeat to Manchester United 1-0, is out tonight with a "slight hamstring injury", Liam Rosenior has confirmed.The Blues line up tonight with a midfield of Enzo Fernandez, Moises Caicedo and Romeo Lavia in what looks like a three at the back formation from the Chelsea boss.TRENDINGStoriesVideosYour SayRosenior's side have endured a torrid run of form as of late, losing their last four in the league and not scoring in the process.Their results have left them looking over their shoulders, with six teams within three points of the Conference League holders.It feels like a must-win game this evening against Brighton, who can leapfrog the Blues if they win.The Seagulls lead with Georginio Rutter up top, fresh off the back of his stunning goal against Tottenham Hotspur to earn his side a point at the weekend.LATEST SPORTS NEWSChampionship clubs reject VAR alternative next season as EFL sides take stance against technologyRonnie O'Sullivan in cruise control after impressive first session at CrucibleBritish Olympic runner completes Boston Marathon while 22 weeks pregnantSpeaking ahead of tonight's game and arguably the biggest seven days in Rosenior's tenure so far, the Blues boss said: "It's a massive week."It's what you're in football for, key games. We've got a huge game [against Brighton], and then we go into an FA Cup semi-final against a Leeds team in form."That's why we're in football, that's what we want. Now is the time for us to deliver, and that's what we have to work towards."The Chelsea manager called for his side to bounce back after their defeat to United and end their horrid form.He said: "It's about our standards, it's about our performances. We have to arrest this run of form. We haven't won enough games recently - that has to change."If you start thinking about the repercussions, you're not focused on what you're doing. We have to focus on the game. We have to focus on the way we play, and we have to make sure we win games."That's what this club demands, rightfully so, and it's what the fans expect. You can't speak about the long term if you're not doing the job in the short term. "Being respectfully honest, we haven't done well enough in recent games. That needs to change, and that's on my shoulders as the head coach."Brighton manager Fabian Hurzeler spoke about the pride he has felt with his side's form, turning a 13-point deficit behind Chelsea to just one ahead of tonight's game.The Seagulls boss said: "I'm impressed by the character, by the resilience the team showed, especially how they stuck together, how they have held each other accountable, how they work in every training session. "They went through a tough period. But they showed great resilience. They showed an unbelievable connection between each other. Sometimes the social bond between people can create more than quality can. And that's the main focus we try to have in the final part of the season. "I am really happy for the players, happy for the staff because they do great work in the shadows. I think it's togetherness that we showed, and now we are in a position where we should really embrace what we all worked hard for. "Now it's about enjoying these moments, enjoying these kinds of games because I think it's a great opportunity for us to grow."Our Standards: The GB News Editorial Charter