Following the 2006–07 season, on 11 August, Le Tallec, alongside teammates M'Vila and Camara, signed his first professional contract, agreeing to a three-year deal.

[citation needed] Though on the first-team, Le Tallec began the season with the club's Championnat de France amateur team.

He appeared in 22 matches, scoring four goals, helping the side finish 1st among professional clubs in their group, thus qualifying for the playoffs, where they lost to Lyon in the semi-finals.

[3] Following the season, news came that Le Tallec had become unsettled at Rennes, primarily due to his limited first-team opportunities at the club.

Two months later, on 8 August 2009, another German club, Borussia Dortmund, announced that they had signed the player to a three-year contract and that he will be gradually introduced to the first team.

[citation needed] In the summer of 2014, Le Tallec moved to Russia and signed with Premier League side FC Mordovia Saransk.

By the winter-break of the 2015–16 season, coach Miodrag Božović, a specialist of Russian football as he had just spent 8 years coaching in Russian Premier League, was in held of Serbian side Red Star Belgrade, who were forming a strong team in order to take the title from their main rivals FK Partizan, who had become chronic winners in the last decade, and in that built-up of the team, Božović made a priority of signing both Mordovia players, Le Tallec and Mitchell Donald, and both ended up moving to Belgrade.

[12] While with Red Star Belgrade, Le Tallec made 104 appearances and scored 7 goals in all competitions and won 2 Serbian SuperLiga titles, between 2016 and 2018.

[21] Le Tallec appeared in all five matches, scoring four goals, one against Haiti,[22] a brace against Tunisia in the Round of 16,[23] and one against Spain whom defeated France on penalties in the quarterfinals.

[28] At the tournament, held in Ukraine, Le Tallec appeared in all four matches, helping France reach the semi-finals before suffering defeat to England.

[33] On 24 April 2024, Le Tallec was appointed as an advisor to the chairman of the board of the Russian champions Zenit St. Petersburg, responsible for partnership and scouting in Europe, Africa and the Near East.