It hasn't been an easy start to Johnston's reign as manager of Kilmarnock and the challenges don't come much bigger than Saturday's clash at Rugby Park against Scottish champions Celtic in front of the live Sky cameras.
Having seen them play in their last two league fixtures at home to Inverness Caley Thistle and then last weekend at Firhill against Partick Thistle, Killie's biggest problem right now is how they start games.
They were slow and cumbersome for the entire first half against Terry Butcher's men and were fortunate to only be one goal behind at the interval.
It was no surprise to me that after getting an equaliser they gave away another goal to lose all three points.
Similarly, they were outplayed for the majority of the opening 45 minutes against Partick Thistle but were able to raise their game in the second period to claim a point.
After enjoying a wonderful season with Queen of the South, Johnston has yet to convince the Kilmarnock fans that he can reach the heights of his predecessor Kenny Shiels.
I was surprised to hear them chanting, "you don't know what you're doing" when he substituted Rabiu Ibrahim late in the game.
It's true to say that the Kilmarnock fans are an angry bunch these days and have very little patience.
The majority didn't agree with chairman Michael Johnston when he sacked League Cup winner Shiels and it doesn't help the new manager's case when he has still to guide his team to a victory after seven games in the SPFL.
Losing tamely at home to Hamilton Accies in the League Cup was a blow to potentially going far in that tournament and generating some much-needed revenue for the club.
It was no surprise to see Kris Boyd getting back on the scoresheet at Firhill.
It seems to me to be the most ineffective use of his talents to play him as a lone striker.
After a poor 45 minutes against Thistle when he was isolated for long periods, he came alive in the second half with a headed goal and was unlucky not to score again.
In contrast to the pressure Johnston is under, his opposite number deals with constant demands on his team to get results.
Neil Lennon has just started another Champions League campaign and no doubt will have one eye on next Tuesday's mouth-watering prospect of Barcelona at Celtic Park when he considers his starting eleven.
One man who needs game time is Finnish Striker Teemu Pukki. Signed from Schalke on a four-year deal, the 23-year old has the potential to score at any level.
A combination of his international experience and pace suggests he'll get the nod over Antony Stokes for Champions League clashes but Lennon is determined his team can keep up a winning habit in Ayrshire.
Anyone who takes his foot off the gas by considering this fixture a low-key affair will surely be left out, and given the quality of strikers on view, I expect more than a few goals at Rugby Park on Saturday.