Alan Judge, Andreas Bjelland, John Egan and Henrik Dalsgaard could be set for international caps tonight with Denmark and the Republic of Ireland.
Bjelland and Dalsgaard will be hoping for game time in the first of two warm-up friendlies before this summer's FIFA World Cup in Russia. The Danes face Scandinavian rivals Sweden in Solna, just north of Stockholm, at 6.45pm English time.
Dalsgaard last appeared for his country in a 1-0 win over fellow World Cup participants Panama on 22 March. Bjelland was last used in November 2017 during a 5-1 win over the Irish during UEFA's qualification stages for the World Cup.
Judge and Egan are preparing to play a part in Republic of Ireland's final summer friendly against USA, an 8.08pm kick-off at the Aviva Stadium in Dublin.
Judge came on in the last friendly for the boys in green as a 70th-minute sub for Shane Long, who misses out tonight through injury. Egan's last appearance for the side came in a friendly against Scottish top flight champions Celtic, a special testimonial for Scott Brown for which no caps were awarded.
Tonight's match will be John O'Shea's 118th and last appearance for his country and home fans will be celebrating his time in the green of Ireland.
The FAI have also announced the use of special rainbow shirt numbers in support of LGBT rights.