Leigh Griffiths has scored 33 goals in just 40 matches for Celtic this season.
Johnson, who used to play for Celtic and currently works as Blackburn Rovers’ head of recruitment, claims that Griffiths’ form will have attracted the attention of side’s south of the border.
Griffiths has slammed in 33 goals in just 40 matches this term, and Johnson feels that anybody with that record will attract attention.
“If he keeps banging in the goals for Celtic someone is going to take a punt on him,” he said.
“If you are challenging Henrik Larsson’s and Brian McClair’s record (of 35 league goals for Celtic) you must be doing something right.
"Putting the ball in the net is the hardest thing. It doesn’t matter where you are. If he does it then well done to him, fair play to him, it is a hard knack.”
Griffiths has been Celtic’s most consistent player so far this season, and he has fully established himself as the Bhoys’ main striker.
Many of Celtic’s players have been short of their best, but the 25-year-old has enjoyed his best season in professional football to date.
Without Griffiths’ goals, Celtic’s disappointing campaign could have been even worse.
The Bhoys have struggled to find another potent scorer in their squad, and Griffiths has rescued them on many occasions.
Griffiths only prior spell in English football came with Wolverhampton Wanderers between the years of 2011 and 2014, and he scored 13 goals in 30 appearances.