The central midfielder enjoyed a productive loan spell at Nottingham Forest last season.
"I've not spoken to Erik ten Hag yet. I've not spoken to anyone at the club yet," Garner said in an interview while on international duty this summer.
"From the play-off final, I've gone straight to being with England, so I've had no rest and no break yet. It's been football, football, football.
"It's time for a rest now. I'm not too sure what the future holds."