Reports have been circulating that Srna would be offered to United this January, but his agent is adamant that his client is happy at Shakhtar Donetsk.
''This Manchester United story is only one of many,'' Stimac was quoted as saying in SportSport.
''During the summer we had specific questions, however Srna didn't show enough interest to change club, not even to go on loan.
''He said that his loyalty to Shakhtar is more important than flashy names of possible new employers. And right now, when things are hardest, he must remain.''
The unrest in Ukraine is thought to be the catalyst behind many footballers in the region looking to escape to other parts of the world in order to play their football, but Srna's commitment seemingly remains unwavered.
Earlier in the year, the Croatian captain told Ukrainian media that he had in fact rejected the likes of Bayern Munich and Chelsea in the past in order to build a legacy and family in Ukraine.
''It is true that I have had offers from Chelsea and Bayern in the past, but I listened to my heart to stay in the team, which has grown for 11 years.'' Srna was quoted as saying by ua-football.com in February 2014.
''If I left, I would get more money, but I decided to stick with my heart. In addition, my family wanted to stay in Ukraine.''
The loyalty shown by Srna in the past is hugely admirable in era where players are often labelled as mercenaries, but few could blame him for moving on now, given the situation and his age.
The 32-year-old defender has played over 400 games for Shakhtar in all competitions, scoring 40 goals along the way.