Blackburn managed their first effort on target after just 16 seconds as Lee Williamson fired towards goal from long range.
Williams and Murphy combined again midway through the half but once again the Irish forward could not get his effort on target.
Rovers improved after that and provided Dean Gerken with a lot of work. Tom Cairney and Corry Evans both had shots blocked by the goalkeeper before Rudy Gestede was also denied after finding space from a free kick.
Cairney had another long-range effort tipped wide just before the break as both sides had to settle for a goalless first 45 minutes.