Alamgir Somaj Kollayan KS After the
2019–20 Dhaka Third Division League was delayed due to the
COVID-19 pandemic, BKSP coaches arranged Morsalin's move to
Alamgir Somaj Kollayan KS, to participate in the delayed league season in 2021. In his first year playing domestic football, Morsalin captained the club to promotion as league champions, and also finished the season as top scorer, with 19 goals from 16 matches. During the season, he also registered a hat-trick against Araf Sporting and a super hat-trick against Asaduzzman FA. In 2021, Morsalin was among the 35 preliminary selected players for
FC Bayern Munich's World Squad, however, he failed to make the final team.
Bashundhara Kings 2021–22 season: Mohammedan SC (loan) On 25 November 2021, Morsalin joined
Bangladesh Premier League club
Bashundhara Kings on a three-year contract. While still being a student at BKSP, the initial plan for Morsalin was to train at the club for three years under foreign coaches, and then play in the Premier League. However, club president Imrul Hassan sent him on loan to
Mohammedan SC, during the mid season transfer window, to give him game time. Even after securing a regular place at the Mohammedan SC starting eleven, Morsalin expressed his desire to return to his parent club, stating in an interview ''"I want to focus on coming back to Bashundhara Kings from my loan, be a regular starter there and eventually make it in the Bangladesh national football team. And I've got long-term dreams of playing in a foreign league too if possible in the future.''"
2022–23 season: Return to Kings On 5 December 2022, Morsalin made his debut for Bashundhara Kings, during the
2022–23 Independence Cup final against
Sheikh Russel KC. After 2–2 draw, Kings won the game on penalties, as Morsalin claimed his first title with the club. On 26 May 2023, he netted his first goal for the club in a 6–4 victory over
Sheikh Russel KC. He also registered two assists against
Mohammedan SC in the following league fixture, on 2 June 2023. Morsalin's performances in these two games got him called up to the national team camp ahead of the
2023 SAFF Championship.
2023–24 season: Disciplinary issues On 15 August 2023, Morsalin made his continental football debut by coming on as an 84th-minute substitute during a 0–2 defeat against
Sharjah FC in the
2023–24 AFC Champions League qualifying play-offs. On 19 September 2023, he made the starting eleven as Kings were trashed 1–3 by
Maziya in the
2023–24 AFC Cup. On 20 September 2023, Morsalin and four of his teammates were discovered to have illegally brought in 64 bottles of alcohol by customs officials at
Shahjalal International Airport in Dhaka. This incident occurred upon their return from the Maldives after defeat in the AFC Cup. Despite the initial indefinite suspension of the players, Morsalin, who was reported to be carrying 10 bottles, had his suspension lifted after receiving a Tk 1 lakh fine from his club. Nonetheless, Morsalin was excluded from the national squad for the
2026 FIFA World Cup qualification – AFC first round. He was also left out of the Kings squad for an away fixture against
Odisha FC in the AFC Cup. On 28 October 2023, he returned to the pitch by coming on as a second-half substitute against
Bangladesh Navy in the
2023 Independence Cup. ==International career==