The Edinburgh club revealed that the Czech midfielder, who scored 18 goals for the club last season, had accepted an offer to use the training facilities at Riccarton.
A Hearts spokesperson said: "As with Craig Gordon in the summer, when we heard that Rudi was back home in Edinburgh and looking for a place to train, we were only too happy to offer the use of the academy to him.
"He has been keeping in shape in Prague and wanted to keep things ticking over during his time in Edinburgh."
Skacel ended his second spell at Tynecastle in May in the same way as his first, by scoring in a cup final triumph.
There have been persistent rumours that the free agent will join for a third time but manager John McGlynn warned supporters last month not to get their hopes too high.