Speaking at the conference of Assist, an association that represents IT professionals in health and social care, Granger said it is "time for people to move from the terraces and get onto the pitch".
An Assist spokesman welcomed his comments, "Assist, the profession and all the key players should start moving with the programme and getting involved."
But heads of IT in some NHS trusts have said there is still a degree of confusion about the impact of the national programme. One IT manager said, "There are moves afoot to engage heads of IT but at this stage it is difficult to see what is going on. Until the local service providers are in post, it will be difficult to predict what is going to happen long-term."
A southern England NHS trust IT manager said, "We do not know what is going on. The programme needs better communication at the bottom end."
However, Assist said the programme is already engaging with the IT profession. A spokesman for the association said, "We have reassurance from the national programme that the situation will improve, and that people at all levels will be much more familiar with how things are working out."
A national programme spokesman said it was engaging with the NHS IT community on a number of fronts.