The Senegalese forward was strongly linked with a move to Tynecastle during the winter transfer window when Daniel Stendel was reshaping his squad.
Hearts brought in four players as the German tried to put his stamp on the team having taken over from Craig Levein with the team struggling in a relegation battle.
Donis Avdijaj, Liam Boyce, Marcel Langer and Toby Sibbick all arrived. The latter on loan from Barnsley, Stendel's former club.
However, the English side were not willing to play ball with a deal for Thiam who would have added to the attacking options at the club.
In part two of BBC Scotland’s This Is Our Story: Inside Hearts documentary, it was revealed that Hearts pushed for his signature but ran out of time to get it over the line.
Thiam is now playing in Belgium after leaving Barnsley at the end of his contract in the summer.
It was also revealed, in a meeting between Stendel and owner Ann Budge, that forward Conor Washingston was close to leaving.
The Northern Ireland international was involved in an on again, off again move to an unnamed club.
It ultimately didn’t go through with Washington remaining at the club with Budge revealing he would only leave for guaranteed first-team football.
Staying at Tynecastle saw Washington net in a draw with Motherwell and win over Hibs before the season was cancelled.
A number of players did leave, however, including Glenn Whelan, Jake Mulraney and Christophe Berra which prompted a number of headlines.
Stendel also gave a further insight into his football mindset when he gave the name of the one player he would have signed for Hearts given money was no issue.
Instead of Lionel Messi or Cristiano Ronaldo, he would have brought in Chilean midfielder Arturo Vidal.
Stendel explained that his work rate and ability to tear around the pitch are the qualities he likes in him.
At the time the one time €37million star was playing for Barcelona having signed from Bayern Munich before moving to Inter Milan.
Episode two of This Is Our Story: Inside Hearts airs on Monday, November 16 at 9pm on BBC One Scotland.