Bruno Guimaraes faces a spell on the sidelines through injury just weeks after completing his move to Arsenal.
Following an extended transfer saga, Guimaraes completed a £75million move from Newcastle to the Premier League champions earlier this month.
The 28-year-old signed a four-year contract upon arrival at the Emirates, and made his first start for Arsenal in their 3-0 defeat of Manchester City in last weekend's Community Shield.
Guimaraes was withdrawn at the interval in the curtain raiser at the Principality Stadium, and later sparked concern as he was seen wearing an icepack on his leg during the second half.
Already a doubt as Arsenal kick off their title defence at home to newly-promoted Coventry City on Friday night, recent reports suggest Guimaraes could miss multiple fixtures in the early part of the campaign.
The news will come as a major blow for Mikel Arteta, with the Spaniard already without the likes of Jurrien Timber and William Saliba through injury.
We've taken a look at when the Brazil international could be back for the Gunners.
When is Bruno Guimaraes expected to return from injury?
Asked about his marquee signing's fitness ahead of Arsenal's Premier League opener earlier this week, Arteta appeared confident that Guimaraes would at least be part of the matchday squad.
"Let’s see," Arteta said when asked whether Guimaraes would return in time to be involved. "It’s evolving well, but let’s see."
However, it appears that Guimaraes' injury may ultimately be worse than first thought.
According to a report from The Telegraph's Luke Edwards, there is speculation at the club that the midfielder could be out for several weeks.
As such, Guimaraes will almost certainly miss Arsenal's opener against Coventry, and their first away match of the season as they take on Aston Villa on 31 August.
Provided he suffers no further setbacks in his road to recovery, Guimaraes could be in contention to make his Premier League debut for the Gunners when they play host to Chelsea at the Emirates on 6 September.
A hamstring injury significantly curtailed his involvement during the latter half of last season at St James' Park, though it is not clear what the issue he is currently suffering with.
During the period between February and April this year Guimaraes missed a total of 14 games for club and country before returning for Magpies in time for their run-in.
