They were signed by former manager Ole Gunnar Solskjaer in the summer of 2014.
Both spent loan spells at rival Championship clubs during the 2015-16 season and have not travelled on the Bluebirds' pre-season tour to Germany.
"They can look for pastures new," first team coach Paul Trollope told BBC Radio Wales Sport.
"It's not an easy situation for them. They've shown a really good attitude and worked hard through pre-season.
"They've been treated with respect and for all parties, if a solution is found, then it would suit."
Macheda, 24, joined Cardiff from Manchester United in May 2014, and has scored six goals in 27 league games for the Bluebirds.
Le Fondre, 29, signed from Reading on a three-year deal in May 2014 but has scored only three goals in 23 league appearances for the club.
He spent the whole of the 2015-16 campaign on loan at Wolves having been on loan at Bolton Wanderers during the previous season.
Italian Macheda was on loan at Nottingham Forest last season, where he failed to score in three league appearances.
Trollope, who succeeded Russell Slade as Cardiff boss in May, would not be drawn on his future with Wales' coaching team.
The 44-year-old is expected to leave Chris Coleman's staff to concentrate on his role with the Bluebirds.
The former Fulham midfielder wants to add to his squad before the transfer window closes but did not reveal who is targets were.
"I'm not getting involved in any names, whether we are or aren't looking," Trollope added.
"All I can say is we are looking to add a couple of new faces and to add to the group.
"We need the strength in depth, we need the quality and we need the attitude within the squad.
"The emergency loan window no longer being at our disposal probably changes our thoughts a little bit in terms of having to finalise everything by the end of August."