In 2012, he joined Twente, before moving abroad and having stints of varying success with Genk, Hapoel Be'er Sheva, Zulte Waregem, Maccabi Haifa, and Alanyaspor.

Haarlem never attracted any scouts, whereas Argon's under-19 team competed at a higher level against clubs like Ajax, Zwolle, and Emmen.

"[9] Taking his father's advice to heart, Plet gave his utmost dedication that season, and, after a year, he earned a move to professional club FC Den Bosch.

[9] Driven by impatience and a relentless pursuit for playing time, he resorted to signing an amateur contract with Den Bosch.

He made his professional debut for the latter on 6 November 2005, replacing Prince Rajcomar in the 89th minute of a 2–0 loss to Stormvogels Telstar in the Eerste Divisie.

Following Demouge's departure to Willem II, head coach Theo Bos chose Koen van der Biezen as the team's first-choice striker.

Despite gaining first-team experience, Plet departed the club after consultation with his father and agent, due to the fact that he was on an amateur contract and in need for financial independence.

"[9] The team experienced a successful season in sporting terms with Plet being a key player for them, scoring 19 goals in 23 matches and helping them to the national amateur title.

[14][8][9] In July 2008, Plet signed a two-year contract with Eerste Divisie club Telstar, marking his return to professional football.

[12] On 27 May 2010, Glynor Plet signed a three-year contract with an option for another year with Eredivisie club Heracles Almelo to succeed Bas Dost, who had left to Heerenveen.

[12] Plet's impact was also extended to the UEFA Europa League, where he scored crucial late equalisers against Sporting CP (group stage) and VfB Stuttgart (round of 32), resulting in 1–1 draws.

[12] Despite missing his penalty in the shootout during the semifinals against Anderlecht, Genk progressed and ultimately emerged as the cup winners in the final against Cercle Brugge.

[42] On 9 July 2014, Plet returned to Belgium by signing with Zulte Waregem, having previously enjoyed considerable success with Genk.

[46] On 10 August 2014, Plet scored his first league goal for Essevee in a 1–1 draw against Club Brugge, finishing off a cross from Aleksandar Trajkovski.

[47] However, Zulte Waregem had a challenging start to the season, resulting in the team's decline to lower positions in the league standings.

[48][49] During this period, Plet managed to score only one additional league goal, leading coach Francky Dury to relegate him to the bench.

[57] On 4 January 2016, he scored in a match against his former side, Hapoel Be'er Sheva, but later on also received a red card for the second time that season, after a foul on opposing goalkeeper Dudu Goresh.

[58] During the Israel State Cup semi-final, also against Hapoel Be'er Sheva, he scored a brace within two minutes, but later fell out due to an injury, as his team eventually won 3–1.

[64][65] New Telstar head coach Andries Jonker was pleased with Plet's return to the club: "With Glynor, we are bringing in a player with a lot of experience and quality.

"[64] Plet immediately scored on his return debut for the club on 23 August 2019, the final goal of a 3–0 league victory against Excelsior after coming on as a 79th-minute substitute for Reda Kharchouch.

[66][67] On 13 May 2023, Plet became Telstar's all-time leading goalscorer, scoring in a 2–1 league loss to MVV, after having shortly shared the title with Sander Oostrom.

[72] In July 2023, he had decided not to rejoin Telstar, expressing a desire to pursue a career as a sports agent while continuing to play, preferably for another professional club.

In attack, he uses his physicality and technique to hold the ball and create opportunities for overlapping teammates, and has been described as a typical target man.