The Seagulls host West Ham sitting seventh on the Premier League table. Addressing their fitness concerns, Hurzeler admitted the medical room is crowded.
He said, "I don't have great news today. Stefanos (Tzimas) we have to further assess him, but at the moment, it looks like a long-term injury, so another long-term injury for us this season. Not quite lucky with them, but we will find solutions, and we wish Stefanos a quick recovery and all the best. I would say months (on how long he will be out).
"I hope that he (Yasin Ayari) is available. On Sunday, it's not quite sure yet, but there's definitely a chance that he's available.
"(Kaoru Mitoma) he's still an option, so let's see if he's able to train today. He had his comeback to our training sessions, he had a small setback during the training session, not a big one, so hopefully he can train today and then for sure we try to make him as quick as possible an option for us."
Revenge?
Hurzeler and Brighton face West Ham manager Nuno for the first time since last season's 7-0 defeat to Nottingham Forest, with the Portuguese then in charge.
However, the German insists there's no thoughts of revenge and Sunday's meeting has nothing to do with what happened last term.
Hurzeler said, "Nuno's teams are always difficult to beat and definitely was one of the worst defeats in my career so far, but I think it's not about revenge, it's not about me against Nuno, it's about Brighton against West Ham.
"It's a different team, different approaches, different players, so it's really about the players. I focus on my players, I focus on the preparation, I focus on keeping the energy level high, and then let's see what happens."
Baleba improvements
In conclusion, Hurzeler was asked about the performance of Carlos Baleba in the midweek defeat to Aston Villa. The Cameroon midfielder offered some glimpses of returning to his best after a difficult season so far.
Hurzeler, himself, has stated Baleba is struggling after last summer's on-off move to Manchester United, though was encouraged by this week's display.
He said, "I was pleased overall with the performance from him. I think he showed good reaction, although he wasn't able to play for 90 minutes, but there was a step forward, and I think we can't expect in these phases of his career big steps.
"We can't expect like magic performance like we might saw from him last season. It's about doing now the small steps forward, it's about doing the small steps right and then at one time it feels like a big step, but it's really like trying to keep pushing, trying to get like physically back on track, mentally back on track, and I saw a step forward definitely, and therefore I was pleased."