Manuel Pellegrini would usually relish another league match so soon after a defeat but West Ham's injury crisis makes tonight's match against Brighton another headache for the manager.

West Ham's momentum was slowed on Sunday when they were beaten 2-0 by Burnley at Turf Moor, a disappointing end to a lucrative December which yielded 15 points and moved the Hammers away from trouble and into the battle for seventh place.

Pellegrini blamed a lethargic performance on the combination of the short gap between last Thursday's match away to Southampton and a lengthy injury list which had stretched into double figures.

New signing Samir Nasri could make a swift debut, but although Marko Arnautovic returned at Burnley and Pablo Zabaleta could be free from illness in time to face Brighton, Pellegrini is still short of options to rotate players who have faced a heavy schedule.

"When you lose you want to play immediately," Pellegrini said. "But when you have played so many games with the same players - we have had just 15 or 16 players from the (senior squad) and three players from the (academy) - you want to have maybe a little bit more time to recover.

"But at least from Sunday until Wednesday night you have more than 72 hours so I hope the players can do it."

Pellegrini is confident the Burnley match can be nothing more than a blip explained by tired legs.

"We need to do what we did in all the other games," he said. "We played seven games in December, we won five and lost two of them. Now we need to try to recover immediately.

"We need to continue adding points. We play now against Brighton which will also be difficult but hopefully we can see the team we saw in all the other games."

While Zabaleta could boost Pellegrini's numbers, the manager is not expecting anyone else to emerge from the treatment room just yet.

Winston Reid remains out with a knee problem but as yet there is no timescale on returns for Jack Wilshere, Ryan Fredericks, Fabian Balbuena, Manuel Lanzini, Carlos Sanchez or Andriy Yarmolenko.

There had been hopes that Javier Hernandez was close to fitness, but Pellegrini said the Mexico striker needed at least another week before he could return.

West Ham completed the signing of Nasri on Tuesday, with the former France midfielder signing a short-term contract until the end of the season after completing an 18-month doping ban.

The 31-year-old had been training with the Hammers and is eligible to play immediately as his signing came outside the transfer window as a free agent.

Nasri won two Premier League titles while at Manchester City, the second of them coming under Pellegrini, and said he was excited to work with the Chilean again.

"I'm really happy that West Ham and Manuel Pellegrini have given me a chance to be playing again," Nasri told West Ham TV. "I know the manager really well. We won the Premier League title together and I'm really passionate about my job.

"Pellegrini was the biggest factor for me to be joining West Ham. When you're a player, you want the manager to know your quality and want you because he's the one that is going to be playing the team, and knows your quality. It was really important and I'm just looking forward to it.

"I love his philosophy and the way he thinks about football. The guy is a genius. He thinks a lot about everything and he has that mentality about football, and we share the same mentality."