Hartley is serving a four-week suspension for head-butting that expires on September 21, ruling him out of the hosts’ tournament opener against Fiji three days earlier.
The 29-year-old was removed from England’s training squad as a result, with head coach Stuart Lancaster explaining he wanted a full complement of hookers available for the entirety of the World Cup, while also referencing his dismal disciplinary record.
It would take an injury to Tom Youngs, Rob Webber or Jamie George for the door to be opened to Hartley, and Rowntree has been checking up on the Northampton captain in case that scenario arises.
“We never discount the possibility of Dylan coming in, if required, so long as he has served his ban,” Rowntree said.
“Dylan’s fit and I’ve been in touch with him regularly, so I know where he is and he’d be able to come in and slot in if we needed him.”
Hartley has spent his pre-season at Northampton while other players who will not make the 31-man World Cup squad to be announced tomorrow have been present at England’s training base in Surrey.
“Why has Dylan not been here? The guys we’ve had in the last couple of weeks like Tom Croft, Ben Foden and Joe Simpson have not had a lot of game time with us over the last couple of years,” Rowntree said.
“Because of that they needed to come in and see how we’re doing things. Dylan has had a lot of game time with us and I trust Dylan. Dylan played in our last Six Nations match.”
Hartley’s reliability at the set-piece — particularly his laser-guided accuracy at the lineout— has been missed by England during their warm-up matches against France.
The lineout was particularly poor in Saturday’s 25-20 defeat in Paris when Youngs’ throwing was exposed once again while second choice Webber is out of form.
It is against this backdrop that Hartley’s absence is becoming more damaging to England’s chances of making an impact at the World Cup.
Lancaster stated last week that Hartley would only be involved if injury struck the squad.
“There would have to be an injury. We would go with the three hookers that will go and we will put all our time and effort into them,” Lancaster said.
“I’ll certainly not be bringing him into camp. I haven’t had a conversation with him since the last one.”
Meanwhile, Rowntree admits Nick Easter has done everything possible to take advantage of Ben Morgan’s fitness concerns by mounting a late challenge for selection in England’s World Cup squad.
Easter was a central figure in the final-quarter revival in Saturday’s 25-20 defeat by France in Paris, stepping off the bench to drive the fightback with some strong carrying and clever offloads.
England name their World Cup squad tomorrow and now face a choice between 37-year-old veteran Easter and Morgan, who recently played 40 minutes against Les Bleus at Twickenham in his first appearance since breaking his leg in January.
“Nick performed very well against France. He’s good around the group,” forwards coach Rowntree said.
“Unfortunately he missed four weeks of our camp with a back injury, so he’s a bit behind, but he’s got himself back up to speed.
“I thought he had an influential impact off the bench. The back row is already competitive, but then he comes on and performs like that...
“Then you’ve got to understand Ben has not played a great deal of rugby in the last eight months.
“His game against France at Twickenham was massive for him psychologically to get back on a rugby field.
“He’s in the shape of his life, but we’ve still got to understand he has not played a lot of rugby. Nick playing like he did makes competition even fiercer.”