Shona Heaslip of An Riocht, who had hoped to make it three in a row, won't defend her women's senior title at Sunday's Irish Life Health National Cross-Country Championships at Abbotstown.
At the recent cross-country race in Mol, Belgium, the Kerry athlete picked up a foot injury which could see her sidelined for the rest of the winter.
Good news is that Ciara Mageean, who finished a close third behind Heaslip and Kerry O'Flaherty in 2016, will run again this year.
Since August when she finished just outside the medals in the 1500m at the European Championships in Berlin, Mageean has resumed training at her Manchester base.
A surprise entry for the race is American-born Dylan Hassett, who has declared for Ireland. Hassett is based in New England where, between training sessions, she works on fitness projects with children.
She ran a personal best 33 mins 6.92 secs for 10,000m in Portland Oregon last June and in early October, finished fourth in the Boston Women's 10km with a time of 32:38.
Also likely to be in the mix is Fionnuala Ross of Armagh AC who finished fifth last year. In the past few weeks, Ross has set a half marathon best of 74 mins 11 secs in Glasgow, finished third behind Heaslip and Scottish athlete Mhairi McLennan at the Autumn Open in Abbotstown and clocked a personal 33.30 to win the Leeds Abbey Dash 10km.
Other form athletes include Jessica Craig of North Down, who was outside the top 20 two years ago but is showing good form this season. She took the Northern Ireland 10km title in October and, last weekend, won the women's race at the South East Cross-Country Championships at Parliament Hill in London.
Also in good shape is Una Britton who finished eighth in the 2016 championships and ran a strong two-mile leg at the Irish Universities Road Relays last Saturday. Then there's Laura Shaughnessy of DSD AC, winner of the Irish Life Cross-Country in Santry last weekend. Not to be discounted is Newcastle's Kerry O'Flaherty, runner-up for the past two years.
After winning the Autumn Open and the Leinster championships, Clonmel AC's Sean Tobin is aiming to win his first national title in the senior men's race on Sunday.
Behind Tobin in the Autumn Open were Kevin Dooney of Raheny Shamrock, second in the nationals last year, and Kevin Maunsel, a clubmate of Tobin's at Clonmel AC. With William Maunsell and David Mansfield in good shape, Clonmel AC are strong contenders for the team title.
Paul Robinson of St Coca's, who ran in the Irish University Road Relays is a surprise entry for the race, which at 10,000m is quite a bit longer than his usual track distance of 1500m. Also running is the up-and-coming Brian Fay of Raheny Shamrock, who was fifth at the Autumn Open.
Leading the entry for this year's junior men's race is Darragh McElhinney of Bantry AC. Sarah Healy of Blackrock AC, the current European U-18 1500m and 3000m champion, is a strong favourite for the junior women's title.