Gradel did not start a Premier League game for Bournemouth last season and is now at the French club until the end of the season.
The 29-year-old is relishing playing regularly and a return to France.
“I understand the French league and coming back here was not a difficult decision,” Gradel told BBC Sport.
“There was no problems or whatsoever with Bournemouth, but the chance to play regular football was too good an opportunity to turn down,
“Even though it’s tough when you are not getting regular football, but I always enjoyed support from everyone connected to the club.”
The former Leeds United player joined the Bournemouth from French side St Etienne in 2015 and signed a new four-year contract the following year.
Despite a lack for regular playing time for Bournemouth he was part of the Ivory Coast squad at the 2017 Africa Cup of Nations in Gabon.
The winger, who has scored eight goals in 50 appearances for his country, felt his lack of opportunities was going to affect his international career.
“There’s personal desire play regularly for club and country this season, considering the World Cup qualifiers throws up a big competition for places,” he added.
“So my decision [to go out on loan] is based purely on football and ambition. You have to make a strong case for yourself by playing regularly wherever you are.
“It’s what’s best for me and my career because I want to help my country qualify for Russia and play in the World Cup.”
Gradel played in all three of Ivory Coast’s games at the 2017 Africa Cup of Nations in Gabon as the defending champions failed to get past the group stages.
He has played in four African Cup of Nations tournaments with the Ivory Coast and was a member of the 2015 title-winning squad in Equatorial Guinea.
Gradel was also part of the squad for the 2014 World Cup in Brazil, featuring against Colombia.