Declan Rice scored against his former club as Arsenal moved top of the Premier League with a comfortable 2-0 win over West Ham, but both he and Martin Odegaard had to be taken off with injuries.
Rice, who was jeered by the travelling fans at the Emirates Stadium, guided home a first-half opener after Eberechi Eze's shot had been parried but had to be taken off with back pain in the closing stages.
Bukayo Saka made the result safe on his 200th Arsenal appearance when he converted from the penalty spot after Malick Diouf had fouled Jurrien Timber, but a victory which put the Gunners a point ahead of Liverpool also featured another injury to Odegaard.
The Arsenal captain, who had only just returned from a shoulder problem, became the first player in Premier League history to be substituted before half-time in three consecutive starts when he was withdrawn for Martin Zubimendi after hurting his knee in a collision with West Ham's Crysencio Summerville.
Odegaard was able to walk down the tunnel when he was taken off but Arteta later said the midfielder was wearing a brace on his knee and that he was "not positive" about the injury.
His and Rice's injuries are just the latest to affect Arsenal, with Noni Madueke, Kai Havertz, Piero Hincapie and Gabriel Jesus already sidelined, and Bukayo Saka, William Saliba, Ben White and Christian Norgaard having also had spells out.
Odegaard's early withdrawal meant Arsenal fans only had half an hour to watch him and Eze start in midfield together for the first time. The latter missed a glorious chance to open the scoring when he ballooned a shot over in the first half.
Viktor Gyokeres also had chances but couldn't convert a string of cut-backs, while Riccardo Calafiori saw a low shot cleared off the line after it had come back off the post and struck Alphonse Areola.
The host dominated on Arteta's 300th game in charge, with West Ham's only meaningful chance coming in the first couple of minutes, when Niclas Fullkrug headed wide from a corner, as new boss Nuno Espirito Santo was shown the size of his task at the club following their 1-1 draw with Everton in his first game.
West Ham had won their last two visits to the Emirates Stadium but couldn't muster a shot on target this time around as their fifth defeat of a torrid Premier League campaign left them 19th.
What did Arteta say about the injuries?
On Martin Odegaard:"He had a clash knee-to-knee and immediately he was uncomfortable. I just spoke to him and he's not positive about it. He's got a brace on. We'll have to wait and see from the doctors."
On Declan Rice, he said: "He's not alright because he asked me to come off, so that's a shame. He had a pain in his back and he could not carry on, which is something very unusual for Declan, so we'll have to assess him and see how he is."
On healing 'scars' of previous Newcastle and West Ham defeats: "The last two games have been very special in that sense. In Newcastle because we had a history there, a lot of scars and a lot of learnings to take.
"We put that right and then we had West Ham losing two games at home in the previous two seasons. I told them it was a big opportunity, we had very difficult fixtures since the start of the season, some very bad injuries as well, not helping.
"And still the team is there, the team is performing, playing well, winning today with I think absolute dominance and without conceding a goal. So, good to get to international break in this spirit."
Nuno: We have to create unity
West Ham boss Nuno Espirito Santo said:
"Arsenal put us against the ropes. Many parts of the game we weren't really able to go out and run. In parts of the game we defended well, but it was a tough game.
"It's a lot of work, all the aspects of the game we have to work on. This week has been a lot of challenges, a lot of new things and changes. The international break is going to be very useful in terms of settling down the mind and focus.
"All the aspects of the game we have to address. We have to create unity, more togetherness, hard sessions on the training ground trying to correct and improve things.
"It's hard to take conclusions [at Arsenal], and be truthful because we're frustrated. But if you look at the game we were organised and compact, we improve slightly our position on set-pieces against a tough opponent.
"At the same time there were a lot of negatives in possession and we lack a bit of mobility."
Arteta's impressive record at 300 games
- Mikel Arteta picked up his 177th win as Arsenal manager in his 300th game. Only three managers have ever won more of their first 300 in charge of a top-flight English club - Pep Guardiola with Man City (219), Jose Mourinho with Chelsea (196 across two spells) and Kenny Dalglish with Liverpool (185).
- Bukayo Saka's penalty was his 100th goal involvement in the Premier League (55 goals, 45 assists). He is the eighth Arsenal player to reach that milestone and third Englishman after Ian Wright (123) and Theo Walcott (108).
- Arsenal's Bukayo Saka became the seventh youngest player to reach 100 goal involvements in the Premier League (24 years 29 days), and youngest overall in the competition since Romelu Lukaku in February 2017 (23 years 267 days).
- West Ham have now faced more shots on target than any other side in the Premier League this season (34).
- Arsenal's Declan Rice has been involved in four Premier League goals against his former side West Ham (two goals, two assists) - only against Bournemouth (five) has he had a hand in more.
