Carvalho who has featured prominently on Arsene Wenger’s transfer wish-list, will miss the first few months of the season after being diagnosed with a stress fracture of the tibia.
The midfielder was highly instrumental to Portugal’s progress to the final of the European Under-21 championship, where he emerged as the most valuable player of the tournament.
Wenger is said to be a huge fan of the 23-year-old, who has made 60 appearances for Sporting Lisbon and capped by his country 13 times.
The chances of Arsenal signing Carvalho this summer now appears very slim, unless the Gunners are willing to miss his services for 10-12 weeks - being the expected recovery time for his latest injury.
Carvalho reportedly has a release-clause of around £25million in his contract, but with this latest lengthy injury, Lisbon would be willing to accept a reduced fee.