A player dubbed Manchester United 's worst-ever signing by Paul Scholes has fired back after suggesting that the midfielder's success was largely down to one of his teammates. Australian goalkeeper Mark Bosnich was brought to Old Trafford by Sir Alex Ferguson in 1999 as a potential successor to Peter Schmeichel . However, he faced a challenging stint at Old Trafford after an impressive seven-year spell at Aston Villa . Despite contributing to United's league triumph in his debut season, his time at the club was marred by troubles and he was replaced by Fabien Barthez . Scholes previously pinpointed Bosnich's transfer as the club's worst . Bosnich has now retaliated, insinuating that his old colleague owed much of his achievements to playing alongside Roy Keane . The 53-year-old also queried why Scholes didn't make more of an impact with England on the international stage. Speaking to former United and Wrexham shot-stopper Ben Foster on the Fozcast podcast, Bosnich said: "Scholesy was an exceptional player but he was very fortunate, in my opinion, to play with someone like Roy Keane. Roy Keane was much underrated as a player. "He had that hard man image, but he's a much better player than people give him credit for. I think when he [Scholes] got the right partner in midfield, he was far better. I thought he should have done a little bit more for England, really." Scholes didn't hold back when discussing Bosnich's poor professionalism on The Overlap podcast last September. He recalled the keeper's troubled second stint at United after first joining the club at the age of 17. Bosnich's return to the club was overshadowed by an incident involving a photographer during his stag do, which resulted in his arrest. "I go back to the goalkeepers, when you had to try and replace Peter Schmeichel, which is always going to be difficult," Scholes said. "We had a few. I was thinking [Massimo] Taibi, Mark Bosnich. "I thought he was a good keeper at Villa, Mark Bosnich. He came to us, and he was so unprofessional. Honestly, it was ridiculous. In shooting practice, you normally have like 15, 20 shots. After three shots, he's knackered, 'Oh no, get someone else in'. "I never realised he couldn't kick a football. I've never seen anything like it. We played Everton away, first game of the season, and none of us picked up on it. He couldn't reach the halfway line. "There was no wind, it was a perfect day. But when you look at his feet, size 14s, honestly, he was just kicking the floor all the time. Disappointing." After leaving United, Bosnich became second choice at Chelsea behind Carlo Cudicini but faced a ban from football in September 2002 after a positive test for cocaine. It took him six years to return to the sport, eventually playing for Central Coast Mariners in Australia before turning to punditry. Bosnich lavished praise on United icon Ryan Giggs, naming him as his greatest ever teammate during his chat with Foster. He not only commended Giggs for his extraordinary abilities on the pitch but also highlighted his generosity off it. "When I first met him, I was 16 or 17, and we played a game at the Cliff [training ground]," Bosnich said. "I remember Fergie walking up to me, and he said, 'Come and have a look at this kid at number 11.' "It was like somebody watching Jack Nicklaus play golf for the first time or Tiger Woods and you think 'Wow'. His father was an exceptional rugby league player for St Helens so he had that wonderful balance and running. As soon as he turned up at 15 or 16, everyone's going, 'Play him, play him'. "For me, he was an outstanding lad. If you rang him up at three in the morning and said, 'I've got a problem and I need your help,' no matter what it was, he was there for you." Join our new MAN UTD WhatsApp community and receive your daily dose of Manchester United content from Mirror Football. We also treat our community members to special offers, promotions, and adverts from us and our partners. If you don't like our community, you can check out any time you like. If you're curious, you can read our Privacy Notice.