Kim Kallstrom is set to miss Arsenal's crucial upcoming fixtures with a back injury after signing for the club on transfer deadline day.
The 31-year-old Swede, who has joined the Gunners on loan from Spartak Moscow, sustained the injury before arriving in north London and the club was aware of it before it completed the move.
Goal understands that Kallstrom, who was Arsenal's only January arrival, will miss the club's immediate upcoming matches but is not set to be sidelined for two to three months as has been reported in his native Sweden.
Scans during the former Lyon star's medical on Friday confirmed an injury to the midfielder's back, which will likely see him miss crucial fixtures against Liverpool, Manchester United and Bayern Munich.
Kallstrom did not train with his new teammates ahead of Sunday's clash with Crystal Palace at the Emirates.
Aaron Ramsey and Jack Wilshere will both miss the visit of Tony Pulis' side to the Emirates, with Mathieu Flamini also out due to suspension.