Pléa made his senior debut for Lyon on 7 October 2012 in an away Ligue 1 match against Lorient, coming on as a substitute for Bafétimbi Gomis in the 90th minute; the match ended in a 1–1 draw.
Nice
Pléa left Lyon and joined Nice in the summer of 2014 in search of more game time in a deal worth £450,000. Under his first manager at Nice, Claude Puel, he was moved into the middle of the park and began to flourish first under Puel and then even more so under his successor Lucien Favre. On 20 October 2016, Pléa scored the only goal in the 1–0 away victory against Red Bull Salzburg in the 2016–17 UEFA Europa League Group I match. That was Nice's first-ever UEFA club competition away win, having previously gone 15 UEFA club competition away matches without a win. 3 days later, he scored a hat-trick in a Ligue 1 match as leaders Nice won 4–2 at Metz to maintain their advantage at the top of the table at four points. On 20 February 2017, Pléa underwent arthroscopy of the right knee in Lyon, which would likely put him out of action for five months. Eight days earlier, he had injured his right knee during the first half of a Ligue 1 match against Rennes and had to be substituted in the 43rd minute. As of 21 February 2017, he was Nice's top Ligue 1 scorer and was 5th in the Ligue 1 top scorers' chart of the 2016–17season with 11 Ligue 1 goals. Playing alongside Mario Balotelli, he proved much more than a wingman by notching 27 goals and nine assists across the 2016–17 and 2017–18 Ligue 1 seasons, helping Nice finish as high as third in 2016–17.
Borussia Mönchengladbach
In July 2018, Pléa joined Borussia Mönchengladbach on a five-year contract. The transfer fee paid to Nice was reported as €25 million. He made his debut for the club against BSC Hastedt in the first round of the DFB-Pokal on 19 August 2018 and scored a hat-trick as Gladbach cruised to an 11–1 win. He scored his first Bundesliga goal for the club on 1 September, securing a 1–1 draw away to Augsburg. He finished his debut season as the club's top scorer with 12 league goals and 15 across all competitions. The following season, Pléa was praised for adding a creative edge to his attacking output, contributing eight goals and seven assists in his first 22 Bundesliga appearances. In the club's match against RB Leipzig on 1 February 2020, Pléa opened the scoring and then got his first two yellow cards of the season and was sent off as Gladbach fell to a 2–2 draw after leading 2–0. On 31 May, he scored his tenth league goal of the season season and provided assists for both of Marcus Thuram's goals in a 4–1 victory over 1. FC Union Berlin.
