Hearts boss Craig Levein admits he will have to make room in his side for in-form Jimmy Dunne even when skipper Christophe Berra makes his return from injury.

The Jambos manager has revealed an agreement in "principle" to extend the centre-back's loan until the end of the season has been struck following talks with Burnley boss Sean Dyche.

The 21-year-old has impressed since moving to Tynecastle in the summer.

He has started all 13 games the Jambos have played since his arrival and was rewarded for those displays with his first Republic of Ireland call-up earlier this month.

Dunne was signed as an emergency replacement for Berra when the captain suffered a hamstring tear that was expected to rule him out for up to six months.

He is due back at Turf Moor next month and Levein previously admitted he would only consider stretching his loan out until May if he could guarantee him enough game time.

But the manager now says Dunne is playing so well there is no way he can leave him out, even if Berra does make an incredible return three months early in the coming days.

"I think Jimmy's done that well that I'd find a place for him," said Levein. "I've spoken to Sean at Burnley and we're going to speak again in January.

"In principle we felt it was quite a good idea for him to prolong his stay here.

"I've not bottomed that out completely so I'll do that once I get past these games leading up to the winter break."

Berra's recovery is another massive boost as Levein looks to get his side back on track following four games without a win, while frontman Steven Naismith is also due back from his knee injury imminently.

The Tynecastle boss – whose side have been knocked off top spot by Celtic on goal difference – said ahead of Saturday's trip to St Mirren: "Christophe will probably be first back. He's in for full training for the first time today I believe. Steven Naismith will be following him some time in December, so I'm hopeful of having those two back fairly soon.

"Well it was Christophe's thoughts (that he would be back for the Rangers game on December 2). We've got a bounce game next week and I think he'll play part of that and we'll see how he responds.

"If it's good, then with someone of his experience and quality I want him back in the team as quickly as possible.

"The good thing is he is a sensible guy and he'll know when he's right. It will be guided by him more than anything else."

John Souttar, Uche Ikpeazu and Jamie Brandon also remain on the sidelines but Levein has no plans to add to his squad in January other than the already-agreed signing of striker David Vanecek from Czech outfit Teplice.

He added: "If I can get five long-term injuries back plus David Vanecek, that's six new players.

"Touch wood we don't get any more injuries, but then I've got a huge headache on who to select in a good way because then the quality of the squad will be back up to where it was in August time."