Arsenal pair Shkodran Muustafi and Aaron Ramsey have been ruled out of the Gunners' midweek clash with West Ham on Wednesday night as a result of ongoing injury concerns.
Having recovered from a hamstring injury already this season, Mustafi lasted just 15 minutes against Manchester United just over a week ago and missed Sunday's draw with Southampton.
Ramsey played 90 minutes against Southampton but finished the game nursing a strain.
Theo Walcott is expected to be fit and available for Wednesday following his absence against his former club after a calf complaint against BATE Borisov in the Europa League a few days earlier, with long-term absentee Santi Cazorla the only other player definitely missing.
Mustafi is termed by manager Arsene Wenger as being 'not completely ready', while Ramsey is only considered to be a short-term loss. Both could be back by the weekend.
For now, it increases the chances that Jack Wilshere will start a Premier League game for Arsenal for the first time since May 2016, 19 long months.
The 25-year-old has played regularly in the Europa League so far this season, but has only been used a substitute in the Premier League until now. He replaced Granit Xhaka after 69 minutes on Sunday and Ramsey's absence leaves space for him the starting line-up against West Ham.
In West Ham, Arsenal face an opposition on a high after pulling off a shock win over Chelsea on Saturday. That much needed victory was new manager David Moyes' first since taking charge last month and lifted the Hammers to 18th, in the relegation zone on goal difference alone.