In 2006, he left for the chief scout role at Newcastle United, where he met Nigel Pearson. He followed Pearson to Leicester City in 2008 and Hull City two years later, and then accompanied him on his return to Leicester, whereby he was made assistant manager.[2] After Pearson was sacked in 2015, the club's board retained all of his staff, including Walsh.[4]
Walsh scouted obscure players such as Riyad Mahrez, Jamie Vardy and N'Golo Kanté for Leicester, and their contribution to the club's success in the 2015–16 season ostensibly led Arsenal to express an interest for his services. He had a £1 million release clause written into his contract.[5] On 8 May 2016, a few days after the club secured their maiden Premier League title, both Walsh and assistant manager Craig Shakespeare agreed to extend their contracts with Leicester City.[1]
In November 2017, Walsh's job was reported as under pressure. Everton had spent £150 million on new players over the summer but found themselves in danger of relegation and were eliminated from the UEFA Europa League.[7] In addition to the expensive players that Everton signed, Walsh also recommended Hull duo Andy Robertson and Harry Maguire for a combined £20 million and teenage Norwegian striker Erling Haaland for €4 million; Everton rejected the trio, whose values soared years later.[8] On 16 May 2018, Walsh was relieved of his duties, being replaced by Marcel Brands.[9]