Having pondered resignation for some weeks, he reached his decision after defeat against Lancashire last Tuesday in the NatWest quarter-final. That failure effectively leaves Notts with only a first-division spot in next year's one-day National League to aim for.
Given county cricket's reluctance these days to grant lengthy tenure to any leader deemed unsuccessful, the change was not unexpected. Informed opinion at Trent Bridge suggested that the transfer of power would happen at the end of the season and Johnson, 33, one of the best liked and most respected seniors on the circuit, has at least stood down with dignity in his own time.
``It was one of the toughest decisions of my life,'' he said, ``and I was just beginning to doubt whether I was still enjoying playing.''
Gallian, 27, who has captained the Australian Under-19 side and Oxford University, said: ``It's a great challenge and a great honour. I hope I've already had time to earn the players' respect.''
After championship finishes of 17th and 13th under Johnson, Notts, losing six of 11 games this year, now lie 16th. The problem has again been with the batting, no player averaging over 40. Johnson, his concentration apparently distracted, has six times fallen between 45 and 70 when big innings were crucial. ``Now I'll be there to give Jason 100 per cent,'' he said.
Leicestershire, meanwhile, have confirmed that they will be taking disciplinary action against Chris Lewis following his ill-considered criticism of the England selectors this week.
Lewis was left out of the 37-man provisional World Cup squad after playing in two Texaco Trophy matches against South Africa earlier this season.
After Leicestershire's NatWest Trophy quarter-final victory over Warwickshire on Tuesday, Lewis said the squad was not picked on ``cricketing ability'' and described the selectors as ``full of ****''.
David Collier, Leicestershire's chief executive, said: ``Chris regrets what he said but realises that comments of that nature are unacceptable. There are mitigating circumstances, which we will be taking into account, but the club will be disciplining him.''
Lewis is recovering from a back injury and is not playing in Leicestershire's current championship match, the first day of which was washed out, against Lancashire at Old Trafford.