Thailand coach Mano Polking has called up Sumanya Purisay to replace Sarach Yooyen in his King's Cup squad.
BG Pathum United midfielder Sarach was injured during their 2-2 draw with PT Prachaup in Thai League 1 on Sunday.
"It is a pity that we will not have Sarach but I think his absence won't affect our team much because Sumanya has been playing very well for Chonburi," Polking said yesterday.
The War Elephants, led by Japan-based stars Chanathip Songkrasin and Supachok Sarachart, arrived in Chiang Mai yesterday.
The four-team tournament will be held at Chiang Mai's 700th Anniversary Stadium from Thursday to Sunday.
Thailand will open their campaign against Malaysia on Thursday night with Trinidad and Tobago playing Tajikistan earlier on the same day.
The winners will meet in the final and the losers face off in the third-place play-off on Sunday.
Meanwhile, big-spending Port were held to a scoreless draw by bottom club Nuangbua Pitchaya in Thai League 1 on Sunday.
Bangkok United's match against Ratchaburi was called off after 53 minutes due to a heavy downpour when the score was 0-0.