This file photo taken on November 24, 2016 shows Brazil's Chapecoense players posing for pictures during their 2016 Copa Sudamericana semifinal second leg football match against Argentina's San Lorenzo held at Arena Conda stadium, in Chapeco, Brazil. [Photo/VCG]

The Portuguese champions had invited the tragedy-hit club from southern Brazil to compete for the annual Eusebio Cup in Lisbon on July 22.

In a statement issued on Wednesday, Chapecoense said it was forced to withdraw from the fixture due to Brazilian Serie A commitments.

Chapecoense are due to play Santos away on July 19 before a home clash against Vitoria four days later.

Seventy-one people died, including 19 Chapecoense players and all of the club's coaching staff, when the chartered plane in which they were travelling crashed into a hillside in Colombia last November.