Danny chatted to children having physiotherapy as he helped to launch the newly redesigned rehabilitation centre.
The 26-year-old was there on behalf of rugby charity Wooden Spoon, which donated £40,000 to give the gym and treatment rooms a much-needed makeover.
The brightly-decorated room features colourful artwork of animals showing off their sporting skills, which young patients have helped hospital arts charity Lime to design.
Danny said: "Everyone knows when you're a child and you have to go in to hospital, it's quite a daunting process.
"The fact they've had the children helping to design it themselves makes it a bit more fun for them to get rehabilitated and heal faster.
"Now it's somewhere more exciting for them to go."
Among the patients he met was 13-year-old Mohammed Abdullahi, who is recovering from surgery on his foot.
Danny said: "I was chatting to him about his rehabilitation.
"He said he was getting put through his paces."
Mohammed, from Hulme, said: "I came in today expecting a normal physio session so it was an amazing surprise to get to meet Danny.
"I hurt my foot playing football and Danny chatted to me about when he injured himself playing rugby. It was great to meet him."
Danny later took a tour of the wards to meet more patients and families.
Wooden Spoon, which supports socially, physically and mentally disadvantaged children, is one of the biggest funders of medical treatment centres in the UK.
Mark Fearn, chairman of the charity's Manchester and Cheshire region, said: "It has been an absolute delight to work with the hospital and meeting the children who had an input into the design work.
"The art work looks fabulous and I am sure it will make the children's visit to the rehabilitation centre that much more pleasant."