Former Manchester United and Fiorentina striker Giuseppe Rossi believes he is still capable of playing in Serie A and remains angry about the conclusion of his professional career.The ex-Italy international, who trained with his former club United earlier this year following several months out of the game, saw his career derailed in 2018 by a failed drug test while playing for Genoa.Released by the club at the end of the 2017-18 campaign, he later picked up a warning, avoiding a one-year ban after protesting his innocence, but has since been unable to find a club. Article continues below Editors’ Picks What is Manchester United’s ownership situation and how would Kevin Glazer’s sale of shares affect the club? Ox-rated! Dream night in Genk for Liverpool ace after injury nightmare Messi a man for all Champions League seasons – but will this really be Barcelona’s? Are Chelsea this season’s Ajax? Super-subs Batshuayi & Pulisic show Blues can dare to dream Born in New Jersey, to where he has since returned following his sessions with United, the 32-year-old revealed that he felt like he had unfinished business with the top division in Italian football.”I’m not finished,” the ex-Villarreal man told Sky Sport Italia. “On the contrary, I get a headache from being angry that I am not playing. “I want to show these people that I can return to the levels that everyone knows I am capable of. I want to and can still play in Serie A “.Signed by United as a teenager in 2004, Rossi spent three seasons on the books at Old Trafford but was limited to only 14 appearances in total, spending stints on loan during his tenure with both Newcastle and Parma.He moved to Villarreal in 2007 and scored on his debut against Valencia, going on to help them to a top-four finish in La Liga and Champions League football.However, his spell was marked by a number of serious injuries, namely two different lay-offs with an anterior cruciate ligament injury that kept him out for a total of 16 months.He joined Fiorentina in January 2013, but left four years later having made only 42 games due to a further succession of injuries and additional loans with Levante and Celta Vigo.At international level, Rossi won 30 caps for his country and was the Olympic Golden Boot winner in Beijing in 2008, as well as a member of their squad for the 2009 Confederations Cup.