The injury curse stalking Kieran Gibbs struck again at St James' Park, where the young England left-back lasted a mere 18 minutes before succumbing to his latest set-back, damaged medial knee ligaments. He is likely to be sidelined for a few weeks, but the outlook for two other players is finally more positive.
Robin van Persie (ankle) and Aaron Ramsey (having recovered from a double leg-break) are both scheduled to return to full training at the end of next week. Thomas Vermaelen, though, continues to need treatment on his Achilles injury and no date has been set for his return. Abou Diaby has an ankle injury and Emmanuel Frimpong (knee ligaments) is a long-term absentee. Manuel Almunia (elbow) is still a couple of weeks away but may struggle anyway to reclaim his place in the starting XI.
Laurent Koscielny made an impressive return at Newcastle after injury, but Jack Wilshere completes his three-match domestic ban and is ineligible to face the Hammers.
Possible Starting XI: Fabianski; Sagna, Koscielny, Djourou, Clichy; Song, Fabregas, Denilson; Walcott, Chamakh, Nasri.
West Ham United
Captain and former Arsenal central defender Matthew Upson should be fit to face his old club after revealing that he was only substituted against Newcastle last week as a precaution to protect his hamstring.
Striker Frank Nouble could be among Avram Grant's substitutes, having been recalled from his loan spell at Swansea City.
Frederic Piquionne is a doubtful starter with a leg injury, while Jack Collison, Zavon Hines and Peter Kurucz (all knee injuries) are ruled out, as is Thomas Hitzlsperger (thigh).
Of the eleven who started against Newcastle, only Da Costa, Parker and Cole lined up for the kick-off against Stoke as Grant took the opportunity to rest players and give others the chance to press their claims. With Premier League points at stake again on Saturday, expect extensive changes again as some of the fringe players drop out.
Possible Starting XI: Green; Gabbidon, Upson, Da Costa, Jacobsen; Parker, Noble, Behrami; Obinna, Cole, McCarthy.
Guns are blazing again
If losing to Chelsea and the inevitable Didier Drogba goal at the beginning of the month was a knock to their title aspirations, Arsenal have shown over the subsequent four October fixtures that their confidence, form and credentials remain intact. Consecutive victories over Birmingham City (2-1), Shakhtar Donetsk (5-1), Manchester City (3-0) and Newcastle United (4-0) - the latter two away from home - have set the Gunners up nicely to finish the month with a fifth straight win over London rivals West Ham United at the Emirates.
Their emphatic success at Eastlands last week helped answer some of the doubts about Arsenal's ability to mix it with fellow title contenders. And while their 43 goals from 14 games in all competitions - averaging three a game - shows that their attacking instincts are as sharp as ever, two successive clean sheets will have been especially cherished by Arsene Wenger. That welcome defensive solidity owed much to the outstanding performances of two goalkeepers - Lukasz Fabianski in Manchester and Wojciech Szczesny on Tyneside. Given the Gunners' well-documented tribulations in the goalkeeping position, that represents a real bonus.
Other plus-points for Wenger have been the return to goalscoring form and fitness of Nicklas Bendtner and Theo Walcott after lengthy injury lay-offs, and the opportunity to give skipper Cesc Fabregas another run-out against Newcastle after his own hamstring problem. With young guns Craig Eastmond and Jay Emmanuel-Thomas also pressing their claims for more frequent appearances, it's been a pretty satisfying 10 days or so for the French tactician.
However, he will know better than most that there is absolutely no room for complacency: his team continue to trail Chelsea by the yawning gap of five points, are only ahead of Manchester United and City on goal difference, and recently skidded spectacularly on the banana skin of a presumed home banker when West Bromwich Albion deservedly turned them over 3-2. They should therefore treat Saturday's visit from the Hammers with deadly seriousness.
Eastenders seeking north London double
West Ham head north across the capital desperate to add to their solitary Premier League victory so far this season. That came, somewhat unexpectedly, against Arsenal's neighbours and arch-rivals Tottenham Hotspur at Upton Park on September 25, so Avram Grant is probably hoping it was a north London omen as he prepares his squad to face a side they haven't beaten in their last seven meetings in all competitions.
He can help inspire his players by reminding them that West Ham have the unique distinction of being the last club to beat Arsenal at Highbury and the first to defeat them at the Emirates. He can also draw encouragement from their performance in midweek when they overcame Stoke City 3-1 at home in extra-time to book their place in the League Cup quarter-finals (where they could yet be drawn against the Gunners).
That cup win - which followed earlier successes in the competition against Oxford United and Sunderland - demonstrated the sort of fighting spirit that Grant will want to build on in the weeks ahead, starting on Saturday. Having trailed Stoke from the sixth minute, the Hammers responded with determination and pluck as captain Scott Parker forced an 84th minute equaliser before Manuel da Costa (96) and Victor Obinna (118) settled the tie in extra-time.
The result lifted the anxiety caused by a third home defeat of the season last weekend against Newcastle, which left the Irons bottom of the table with six points from their nine Premier League games. The one plus for the team in that defeat was Carlton Cole scoring his first goal of the campaign; how they could do with another one - or more - from the striker at the Emirates.