Bath are top of the Premiership, as it stands, having won five of their opening six games.
However they were narrowly beaten 24-20 in torrential conditions against two-times Champions Cup winners La Rochelle at the Rec last weekend in their opening European game.
Prop Archie Griffin suffered a shoulder injury during the defeat which Van Graan said the club needed to do “more research” on, and captain Ben Spencer has been doing rehab work on a hamstring injury, with a decision on his inclusion to be made later in the week.
England flanker Sam Underhill has been back at Farleigh House training as is prop Beno Obano, while Alfie Barbeary continues to be monitored under return-to-play protocols after suffering a head injury.
“The Champions Cup is a big competition, we’ve got three big games in the Premiership coming up over the Christmas period in Newcastle away, Saracens at home Northampton away,” Van Graan said.
“Then we’ve got Clermont and Leinster then we’ve got to go away without English players to Sale and three Prem Cup games before this block ends.
“We’ve got to plan up to the back-end of January.”