Burrows, 28, said having missed out on selection for the FIH Champions Trophy in Argentina later this month, breaking into the 16-player Olympic squad was going to be difficult.
"After being in and out of selections over the past year, when I missed selection for this year's Champions Trophy, I had a good chat with Mark and spent the summer thinking about if I could fully commit to the programme in such a busy and important year for the squad and decided it was time to hang up the stick on international hockey,'' said Burrows, who has 18 test caps.
Thorpe and Burrows, who both attended Kamo High in Whangarei, will still play club and regional hockey.
Thorpe plays for the Maungakaramea club and for Northland in the National Hockey League (NHL). Burrows, a marketing manager for New Zealand Golf, will continue to play for the Somerville club and in Auckland's NHL team.
Petrea Webster, 23, and Melody Cooper, 28, have been added to the 2012 national squad following the retirements.
Webster was in the 2011 national squad and has eight international test caps, which includes playing in the 2011 Argentina test series at North Harbour.
Cooper (nee Rowe) has been based in Australia as captain of South Australia's Southern Suns, leading the team to victory at the 2011 Australian Hockey League.