The 22-year-old Northern Ireland international, who scored the winner in the 2-1 defeat of Sheffield Wednesday, fell to the turf during over-boisterous rejoicing with his team-mates. He is expected to stay in a London hospital for the rest of the week, after shattering the humerus (long upper-arm bone) in his right arm.
Morrow will miss Northern Ireland's next three World Cup qualifiers - in Spain, Lithuania and Latvia - and the re-match with Wednesday in the FA Cup final next month.
David O'Leary, who also played in Arsenal's Wembley victory, has attracted Manchester United to Highbury for his testimonial on 17 May. O'Leary leaves the Gunners this summer after 20 years at the club.
Morrow's absence from the international scene has led to a call-up for Grimsby Town's Paul Agnew, who was named yesterday in the Northern Ireland squad for the game against Spain in Seville next week. The uncapped Agnew, 27, a left-sided utility player, joined Grimsby from the Belfast club, Cliftonville, nine years ago.
A former Arsenal man, Perry Groves, will be out of action for six months after aggravating an Achilles tendon injury. The Southampton winger damaged his tendon in a mishap at home soon after removing his plaster cast, and then caused further harm to his heel by slipping on a shower-room floor when he went to The Dell to report the new injury.
Dick Advocaat, the Dutch coach, has named Frank Rijkaard and Ronald Koeman in his squad for next week's World Cup qualifier against England at Wembley, even though both men are struggling to recover from recent injuries.
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