The Brighton defender has struggled for form since arriving in Glasgow at the beginning of the season, and looked particularly low on confidence during the Hoops’ recent run of one win in six matches across all competitions.
Lennon’s response to the 28-year-old’s slump was to leave him on the bench for the 4-1 win over Motherwell at the weekend, and Boyd is of the opinion that being dropped could be the jolt he has needed to kickstart his ailing stint north of the border.
Speaking to Sky Sports News, the Scottish pundit said: "Shane Duffy has been struggling.
"A lot of people down south have said that Scottish football is easy and have criticised it for a number of years, but a lot of players have experienced difficulties in the past and Duffy is on that list right now.
"He has been struggling but because of the way Celtic play on the front foot, it's natural to drop five or 10 yards as a defender and he's been a bit isolated.
"There's definitely a defender in there with the number of years he's played in the Premier League. Being out of the team on Sunday will be a reality check and it's up to him to force his way back into the team as Celtic have paid big wages for him."
Boyd isn’t the only pundit to have questioned Duffy’s performances in recent weeks.
Former Parkhead goalkeeper Pat Bonner was quick to single the defender out for criticism after last month’s pulsating 3-3 draw against Aberdeen, claiming that the Dons “exploited” the Republic of Ireland captain.
On a more positive note, however, Brighton’s young Irish striker Aaron Connolly has backed his teammate to come good for the Bhoys.
Speaking to The 42, he said: “He’s a brilliant centre-half and he has shown that for many, many years, so a couple of games is not going to change what everyone thinks of him.
“He’s shown for Ireland how good he is and he’s shown for Brighton how good he was and how highly rated he was.”