Now the man of the series in Australia's Ashes domination this summer is very good, outstanding or frighteningly-fast.
There has never been any doubt about the left-arm paceman's bowling ability, only his consistency.
His performance in England's first innings of the Boxing Day Test is another demonstration of how far Johnson has come in his cricketing career.
For much of day one Johnson wasn't terrible, but he was clearly below his best.
He'd bowled 15 overs and returned 0-45.
There were murmurs that after his superb work in this series, perhaps he and not Ryan Harris might be the main candidate to sit out the Sydney Test.
But the point here is that he wasn't spraying his deliveries like he would have in the past.
Then came the second new ball.
Regularly hitting 150km/h-plus, Johnson tore through the English middle order and tail with some genuinely-scary pace bowling.
In nine overs of destruction, he took 5-18.
On Friday morning, he snared 3-4 from four overs, including the crucial wicket of Kevin Pietersen.
England could forget about their goal of reaching 300.
Suddenly, no-one was talking about whether he needed a break.
The rejuvenation of Johnson's career is well-documented, how he overcame injury and a desperate lack of self-confidence to realise his massive potential.
He is now ninth - yes, ninth - on the list of Australian Test wicket takers with 233.
Johnson's Melbourne haul took him past fast bowling legend Ray Lindwall (228).
He also has 28 wickets for the series and if he keeps up his average of four per innings, Johnson will finish with 40.
Only Clarrie Grimmett, Shane Warne, Terry Alderman and Rodney Hogg have taken 40 or more wickets for Australia in an Ashes series.
One anecdote to emerge during this Ashes series is Johnson spending time last year with Australian Victoria Cross winner Corporal Ben Roberts-Smith.
In recounting their time together, the SAS soldier stressed that war is not sport.
But Roberts-Smith said he made the point to Johnson that elite cricketers, like soldiers, have to find a way to get the job done.
There are no excuses. No sooking.
Johnson always had the desire, he just lacked the self-belief.
He somehow found a way to sort that out.
No-one, least of all the man himself, doubts Mitch Johnson now.
THE RISE AND RISE OF MITCH JOHNSON
* Johnson is the leading wicket taker in this Ashes series with 28 at 14.96
* If he continues his average of four wickets per innings, he will become only the fifth Australian to take 40 in an Ashes series
* Johnson now has 233 Test wickets and is ninth on the all-time list
* Three of his 10 five-wicket Test innings hauls have come in this series
JOHNSON'S BOXING DAY TEST, FIRST INNINGS
First new ball - 15 overs, 0-45
Second new ball - nine overs, 5-18
Friday morning - four overs, 3-4
Overall innings - 24-4-63-5
(10th five-wicket haul of his Test career)