Jo Tessem has accused Saints boss Gordon Strachan of favouritism.
The comments, made to a Norwegian football magazine, came before Tessem got a roasting from his national press after a poor performance in Norway's 1-1 draw with Iceland, which saw him substituted at half time.
Tessem, who has started only two matches since Paul Telfer joined the club from Coventry in November last year, said: "You've got to say it, if not you lose your own respect. It's about feeling well. I was treated different to the others. Strachan gave priority to the players he brought to the club. It wasn't competition with the same chances for all.
"You've got to accept some people are against you. It's the first time in a while I have faced a real struggle.
"It can be healthy for your own development. I don't want to be a whimper but I will be passionate.
"I'm at the peak of my career, through the combination of physical fitness and experience. I'm 30 and will not continue playing at this level for too long, so I want to play when I can."
Tessem, a former Norwegian policeman, was signed by Dave Jones in November 1999 from Champions League side Molde for £600,000.
Despite playing in a variety of positions during his time with Saints he found his opportunities limited last season both as a striker and a midfielder.
He started only eight matches but came on 16 times from the bench - scoring his two goals for the campaign against Arsenal and Sunderland to earn two valuable points.
But so bad was his performance in Tuesday's international friendly that one Norwegian national paper gave him a rating of three out of ten and commented: "Had a poor game. Succeeded with little," while another added: "Did not build on his positive game against Japan. Looked clumsy and indecisive."
Sunderland today confirmed that Saints have enquired about the availability of £4m-rated Republic of Ireland winger Kevin Kibane.
Aston Villa, Everton and West Brom are also chasing the 25-year-old, who signed for the Black Cats for £2.5m from West Brom over two years ago.
Sunderland rate the winger in the £3.5-4m bracket but say that could rise if he has a good World Cup with the Republic.
Kilbane is currently away with the rest of Mick McCarthy's squad preparing for their first match against Cameroon next Saturday.
Saints have added another friendly to their pre-season calendar. They travel to Division 3 side Exeter City on Wednesday, August 7. The match at St James' Park kicks-off at 7.30pm.
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