Thomas Barr will relinquish his national 400-metre hurdles title for the first time in eight years as he has withdrawn due to a calf injury.

The 27-year-old Waterford athlete has won the event at the Irish Life Health National Athletics Championships every year since 2011, but is taking no chances with a niggle ahead of the World Championships later this year.

It is two months to the day until Barr's scheduled heat in Doha and the global event is the Irish record holder's priority.

Third at the European Championships last year, Barr is hoping to build on his fourth place finish at the 2016 Olympics in Rio and has shown decent form in the early part of the season.

He was due to run in the heats at Morton Stadium, Santry this afternoon.