Born in Borso del Grappa, Magrin began his career with Serie DBassano Virtus in 1975. He moved to Montebelluna in 1978, where he remained for two seasons. In 1980, he moved to Serie C1 side Mantova, where he remained for one season before moving to newly relegated side Atalanta in 1981. His performances and leadership soon helped the club to achieve Serie Apromotion, winning the Serie C title in 1982, and the Serie B title in 1984, in the process. Magrin made his Serie A debut with Atalanta during the 1984–85 season, and later helped the club to the Coppa Italia Final in 1987, where they were defeated by domestic double winners Napoli; in total, he scored 40 goals for Atalanta in 192 appearances. Magrin was acquired by Juventus F.C. in 1987, as a replacement for Michel Platini in the midfieldplaymaker role, following the Frenchman'sretirement, but decided not to take Platini's number 10 shirt, as the club presidentGiampiero Boniperti advised him to take his own number 8 shirt instead, which had also previously belonged to Marco Tardelli, as a sign of respect and humility. Magrin himself was rather modest about his new role and brushed off comparisons with the Juventus legend. The two seasons he spent with the club were not successful for Juventus, however, due to the club's post-Trapattoni crisis under new manager Rino Marchesi; although he often started in his first season, his second season saw him relegated to the bench with greater frequency, and he subsequently left for Hellas Verona F.C. in 1989. He spent three seasons with the club under manager Osvaldo Bagnoli, before moving back to Bassano Virtus, the club with which he began his career, in 1992, retiring in 1993, after one season.
A creative, technically gifted, and hard-working, right-footed, advanced midfield playmaker, Magrin was usually deployed as an attacking midfielder, or as a winger or central midfielder, and was capable of both scoring and creating goals. Despite his talent in his youth, which even led Platini to say "he's better than me", his career was marked by inconsistency and he failedto live up to his initial potential. Magrin was known in particular for being a penalty-kick specialist and for his incredible accuracy on set-pieces, as well as his use of the bending "knuckleball" technique on free kicks.