Arsenal have doubts over the fitness of Alex Oxlade-Chamberlain and Héctor Bellerín heading into their FA Cup fourth round clash at Brighton and Hove Albion on Sunday. Both players started Arsenal’s last outing when Arsène Wenger’s men ended their long baron streak against the Premier League’s big guns away from home by beating Manchester City 2-0 at the Etihad. But Wenger could be compelled to make changes to his lineup for the trip to take on their Championship Opponents at the Amex Stadium.

“We have basically some uncertainties about [Oxlade-] Chamberlain and Bellerín,” Wenger said at his pre-match press conference on Thursday. “They have tests todays. Bellerin should be available, Chamberlain I’m not sure. Chamberlain has inflammation of his groin problems. Bellerín has an ankle problem.”

While Wenger expects striker Danny Welbeck’s absence with a thigh problem to continue for the next two games, the Arsenal manager stated that it was likely Mesut Özil would be handed his first start since recovering from a knee injury. Theo Walcott could also be in line for a place in the lineup, having made his only start in the past year in Arsenal’s FA Cup third round win over Hull City. And Wenger has suggested that the options at his disposal in attacking areas mean that there could now be regular rotation.

“People reproach you when you have no competition on the bench,” he said. “When there is one, they question you as well. It is true there is competition for places at the moment -- that is a luxury that only a club of our stature can afford. It can make the players better, because the competition inside the club is always very important to keep everybody on their toes. These are players who are in a bit of a special position, it is not their quality that is questioned, it is just the fact they have just come back from long term injuries. The best 11 I have in my head can change every week. We are in a world where competition is vital and competition is just down to performance in the last game.”

One player who won’t yet be coming in the first-team reckoning, however, is Krystian Bielik. The 17-year-old midfielder became Arsenal’s first signing of the January transfer window this week when arriving from Legia Warsaw. But Wenger explained that Bielik needs to build up fitness before he can even be considered as an option.

“No, no not at all,” he responded to a question over whether Belik could feature at Brighton. “He comes just from Poland, just turned 17. He is not fit, because they had the winter break in Poland that is quite long, so he is at the start of getting back to full fitness. He will not be ready for three weeks.”

While Bielik settles in, it now appears increasingly likely that another midfielder may have already made his final outing for Arsenal. Abou Diaby has been beset by injury problems in recent years, and has made just three appearances since March 2013. While he had high hopes of a comeback in preseason, fitness problems have struck again, leaving Wenger with serious doubts over whether to extend the 28-year-old’s contract beyond this summer.

“Abou Diaby is still injured” he said. “At the moment he’s not in a position where he will be ready to play soon, because he is not on the field at the moment at all. We have a decision to make about his contract, yes.”

There is more upbeat news regarding the future of another long-term injury victim. Teenage attacking midfielder Serge Gnabry has not played since last March because of a knee problem, but is now nearing a return to the first team.

“Serge Gnabry is back in full training, but he needs first games in the Under-21s because he has been out for a very long time. But he looks quite promising again, physically and fitness wise he’s OK.”