Liam Flatman is facing a race against time to be fit for the start of Dublin's Leinster SFC defence against Wexford or Louth on May 25, writes Frank Roche.
The Kilmacud defender made his Allianz League debut for Dublin against Galway back in early February, but hasn't featured since.
He took no part as the holders opened their Dublin SFC campaign with a win over Ballymun on Saturday, and joint-manager Johnny Magee has described his hamstring injury as "probably a ten-week job".
As Magee explained, Flatman tore a tendon at the top of his hamstring and the problem has been "going on a while". He has been ruled out of Kilmacud's second round-robin clash against Na Fianna in Parnell Park on Thursday week (8.15).
Crokes are hopeful that Cian O'Sullivan, another non-starter against Mun, will be fit to face Na Fianna. The six-time All-Ireland winner has a history of hamstring trouble but his latest occurrence is relatively minor.
Their opponents have a similar headache, as Na Fianna brushed aside St Sylvester's without the services of two injured Dublin defenders, Jonny Cooper and Eoin Murchan.
Other county stars who didn't feature in club action included John Small for Ballymun against Crokes, Paddy Andrews (still recuperating from his broken jaw) for St Brigid's in their defeat to St Vincent's; Colm Basquel for Ballyboden as they edged past Clontarf; and Stephen Cluxton for Parnell's in their SFC2 defeat to St Mary's of Saggart, albeit the Dublin skipper did take part in the warm-up.
Carlow have confirmed that manag er Turlough O'Brien (20 weeks), coach Steven Poacher (12 weeks) and midfielder Brendan Murphy (12 weeks) have all lodged appeals to the CAC against suspensions meted out by the CHC last week.