(Reuters) - Hooker Luke Cowan-Dickie has left England's training camp in Portugal for family reasons, assistant coach John Mitchell has said, with Tom Dunn likely to make his debut in Sunday's Six Nations opener against France.
Saracens' Jack Singleton is set to travel to Paris as back-up for Bath hooker Dunn.
"Family comes first, and we respect that," Mitchell told BBC 5 Live. "We don't know (if he will be available)... Luke will make that decision."
Jamie George had started in the position in England's last match, a 32-12 defeat by South Africa in the Rugby World Cup final in November.
"We've got Jack, Tom, and Jamie. Tom has really impressed us. He's a hardworking player who gains a lot of respect for the way he goes about his work," Mitchell added.
The 27-year-old Dunn will find out if the long wait for his debut will end when head coach Eddie Jones names his starting side on Friday.
"I think this is my seventh time in the squad. For different reasons, I haven't been able to get my cap," Dunn said.
"I can't control who Eddie picks, but I can control what I do. Hopefully my opportunity will come ... my pride keeps me going. I want to play for England.
"Everyone has their own journey and story, whether it's injury, selection or home life. But I've worked hard and I've kept working hard."
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Peter Rutherfordpeter.firstname.lastname@example.org; +822 6936 1482)