Jack O'Shea, rated alongside the legendary Mick O'Connell as one of the Kingdom's most outstanding exponents of midfield play, readily agrees that the Gaeltacht star is crucial to their prospects of advancing.
And, without him it's not inconceivable they could struggle to beat a Roscommon team which will have gained in confidence from their extra-time win over Leinster runners-up Kildare at the weekend in the last of the qualifier rounds.
Additionally, the respected Sunday Times columnist and RTÉ analyst puts forward the argument that Kerry may not be as well prepared for this game as opponents.
Three years on, the merits of the qualifier system are still being debated. Association president Sean Kelly accepts that there are inequities in terms of the scheduling of some rounds and it's a view GAC chairman Tony O'Keeffe concurs with.
When he took over three months ago the schedule was already in place and his committee has to work within its parameters. Other than the hardship of teams having to play six days after losing in their own championship, the wider issue of the provincial winners being inactive is a further concern.
Striking a balance is the challenge facing association leaders and the high-powered committee the president has put in place to review the hurling and football championships.
That's for the future. More immediately, O'Shea feels Kerry could suffer because of their inactivity in comparison to Tom Carr's side. Indeed, he feels the same about Connacht champions Galway, who were in the same position last year and lost in the quarter-final to Kerry by eight points.
"The two most vulnerable teams next weekend must be Kerry and Galway, from the point of view that it's several weeks since they played a competitive game. In the meantime, all the other teams have played matches. We saw it last year where Galway hadn't the game for a few weeks and Kerry came through the back door system and were much better prepared," he said.
At the time, I felt Kerry had made enormous progress from their drawn game with Cork in Killarney to the day they took Galway on in the quarter-final and won 2-17 to 1-12. O'Shea takes a different view, suggesting they made "a bit" of progress.
"With due respect to the other teams, they got some easy games. They had no real hard game and subsequently it cost Kerry the All-Ireland final. They weren't really tested, they didn't know where their weaknesses lay.''
In brief, he feels the back door system wasn't of much benefit to Páidí Ó Sé's team last year, that it wasn't really beneficial as regards being on a learning curve. However, he accepts that it brought them into the game better match-prepared than Galway were.
O'Shea was in Killarney for the Munster final and wasn't impressed by Kerry. "I thought Limerick started in a whirlwind fashion, but missed a lot of chances which could have put Kerry under a lot of pressure.
"Kerry were poor on the day. I thought it was a few individual performances that brought them through rather than a team performance."
In terms of individual contributions, the loss of Darragh Ó Sé was huge in that game, as much as it had been in the semi-final against Limerick last year when Ó Sé was again injured but brought in as a second half substitute.
"It just showed that if Darragh is not on top of his game, Kerry are vulnerable. I thought the forwards were not able to win the ball in the Munster final. It almost had to be handed them. They were tightly marked. They never looked convincing. I think Kerry have a huge improvement to make."
Like most people, O'Shea said he would have been expecting Mike Frank Russell and Colm Cooper to do better in the Munster final. In the event, they were both replaced in the second half.
In mitigation, he points out that they didn't get a decent supply of possession, especially of the type of ball they like.The explanation, he suggests, was Kerry's lack of dominance out around midfield.
"Darragh Ó Sé is the playmaker, the player who lays the ball on. The bonus was that Eoin Brosnan was very good. He's a very pacy player and I think he would be the ideal partner for Darragh. My understanding is that Darragh hasn't done much, that his match fitness would be suspect. Without him, that could be bad because the Roscommon pair of Seamus O'Neill and Stephen Lohan are strong.
"Roscommon have had a healthy run-in. They had a nice game with Offaly and against Kildare last weekend. They're probably as match fit as they could be. The Kildare game will have brought them on a lot."
If Kerry are to have an advantage, he feels it will be their pace. But this will only materialise if Kerry play up to form, something he feels they haven't managed for quite a while.
And, he knows Tom Carr isn't one to shy away from the challenge, that his knowledge of the Kerry team from his Dublin days will ensure Roscommon's players are well briefed in advance.
The bottom line is that Carr will appreciate this may be the ideal time to catch Kerry, that without having the same level of preparation as his team and not having earned too many plaudits after their Munster final victory, they will indeed be vulnerable.