https://www.fcbarcelona.com/football/first-team/news/2018-2019/18-man-squad-without-umtiti-squad-list
"....The squad for the visit of the club from Bilbao is the following:
Ter Stegen,Semedo, Pique, I. Rakitic, Sergio, Coutinho, Arthur, Suarez, Messi, O. Dembélé, Rafinha, Cillessen, Lenglet, Jordi Alba, Munir, S. Roberto, Vidal and Vermaelen.
Left out are Denis Suarez, Malcom, Samper and Alena with Umtiti missing due to injury.
On Friday the squad trained for the final time ahead of the game against Athletic. All the available players took part in the session along with Inaki Pena from Barca B at the Ciutat Esportiva. Samuel Umtiti did not train due to a knee problem and he will miss Saturday’s game. His recovery will dictate his return to action."
简单来说Umtiti因膝伤缺席了周五的训练，连同Denis Suarez, Malcom, Smper, Alena一起被排除在今日大名单之外。
至于U23确切的回归日期官方还没有公布任何时间，不过相关媒体的报导有稍微提到
http://www.goal.com/en/news/blow-for-barcelona-as-umtiti-facing-months-out-with-knee/1jwmeo0zryx9s1h8xdh3enojfd
"Ernesto Valverde has confirmed Samuel Umtiti has sustained a serious knee injury, which reports in Spain suggest could keep the 24-year-old defender out for several months.Umtiti played the full 90 minutes in Wednesday's stunning 2-1 defeat at Leganes which ended Barcelona's unbeaten LaLiga start but missed training on Friday ahead of the weekend clash with Athletic Bilbao.
The France international is not in contention for the Camp Nou clash against Valverde's former club and, although already suspended, would not have been fit enough for the midweek Champions League match versus Tottenham at Wembley.
"He's got a knee problem so he couldn't have played on Wednesday," said Valverde.
"Let's see how things develop, but hopefully it won't be too long before he's back with us. It's a blow for us."
A report in AS claimed Umtiti had suffered ligament damage in his left knee and may not play again in 2018...."
主帅证实了U23的膝盖伤得不轻，各家媒体都预估需要数个月才能回来，比较夸张的也有预估要明年才能复出。