Celtic duo Paddy McCourt and Niall McGinn have expressed their disappointment via their agent after being subjected to death threats.
An investigation is currently being carried out by Strathclyde Police after a package addressed to 27-year-old McCourt containing bullets was discovered by Glasgow Royal Mail workers on Tuesday.
McGinn, 23, and Celtic manager Neil Lennon also received similar threats last week, which were detected by postal workers in County Antrim and it is said that all three packages were posted in Northern Ireland, where the trio are from.
But the players' representative Gerry Carlile insists neither performer will allow the disturbing threats to obstruct their respective careers.
Carlile told Press Association Sport: "I have spoken to both Paddy and Niall and while both are shocked and disappointed, they are determined this won't derail their efforts on the park.
"Both are encouraged by the support and sympathy they have received from both sides of the divide in recent days.
"However, I hope the PSNI (Police Service of Northern Ireland) and Strathclyde Police are investigating thoroughly and that those responsible are caught and brought to justice swiftly."
The three Celtic targets are Catholic and have represented Northern Ireland at international level but while McCourt and McGinn are favourites of the Windsor Park crowd, Lennon retired from international football in 2002 after receiving death threats.
McCourt and McGinn, both former Derry City players, are in Lennon's squad for Wednesday's SPL clash with Hamilton at New Douglas Park.