Barcelona right back Gabri will be sidelined for at least six months after rupturing knee ligaments during his side's 4-1 victory over Real Zaragoza, the club said on Friday.
"The anterior cruciate ligament and the internal lateral ligament in his right knee have been torn completely," chief of Barcelona medical staff Jordi Ardevol told the club's website.
Motta is scheduled to undergo an operation in the United States next week to deal with his injury.
The good news for coach Frank Rijkaard is that left back Silvinho, who was also carried off with a knee injury at the start of the Zaragoza match, will only be out of action for between three to four weeks.
Ardevol said the Brazilian defender has suffered damage to a lateral ligament, but will not require surgery.
In-form Dutch defender Giovanni van Bronckhorst and Brazilian fullback Juliano Belletti will replace the two injured players in the Barca starting line-up.