Hearts boss hopes pre-season training will give Jambos the edge
Ex-Kilmarnock manager Jefferies was only appointed at Tynecastle at the end of January following the sacking of Csaba Laszlo just a few hours earlier.
Hearts struggled to find their form under the Hungarian in the early stages of last season but still ended up in the top six.
The Tynecastle side return to pre-season training on Wednesday and Jefferies believes he is now fully getting to know his players and their capabilities.
He said: "The advantage that I have this season is that all of the time we spent with the players last season, in trying to get a place in the top six, gave Billy and I an opportunity to weigh everything up. You only really get to know people properly when you work with the boys and get in amongst them in training and in the dressing room.
"Some people surprise you because they are better than you maybe thought – while there are other boys who go the other way.
"That's because you're not working with them on a daily basis, you're only seeing them at games or on television.
"Some people have moved on from the club and we have brought a couple of players in as well. Darren Barr is coming in and we are looking forward to working with him. I have spoken to Yogi and Brian Rice about him and to Steven Pressley and they all said exactly what I thought they would – that he will be a perfect addition to our side.
"Big Kevin Kyle up front will be a handful for defenders and, hopefully, he will come here and show what he is capable of."
Jefferies is keen to improve on fitness levels among his players but insisted: "Everyone does this job differently and that's their prerogative, that's no criticism of anyone. A few of the boys were maybe not as fit as I would have liked but for some it was because they weren't able to do the work because of injury."
Meanwhile, Paul Hartley has opened the door to a return to Tynecastle at the age of 33, saying he would be "very interested" in a move north from Bristol City. Jefferies is interested in the midfielder but any transfer would involve a fee as Hartley's Bristol contract does not expire until June 2011.
"Hearts are without a doubt the third biggest team in Scotland," said Hartley. "Going back there is something that would really interest me."