Sergio admitted “a political thing” meant Kello was left out of Sunday’s 1-1 Scottish Cup fifth-round draw with St Johnstone at Tynecastle and the Slovakian was again missing for Wednesday night’s 4-0 home loss to Celtic in the SPL.
Kello, out of contract this summer, is understood to have turned down a January move to Rapid Vienna for a reported fee of €100,000 (£83,000) which is believed to have irked Hearts owner Vladimir Romanov.
“It’s a tough situation, it’s not a good thing for us,” said Sergio but Shiels, whose Kilmarnock side face Hearts in the SPL at Rugby Park tomorrow, said that he would not have tolerated any such similar boardroom interference.
“I have no sympathy for him,” said the Northern Irishman. “If you have principles in your life and your job is to select the team and that power is taken away from you then you have to leave.
“If my chairman was trying to pick my team I would walk away because he has taken my job away from me.
“I am not criticising Paulo Sergio but, in my opinion, if the chairman ever said to me that I have to pick him or him then he is compromising my position.
“I have two keepers fighting for the number one slot. If the chairman says to me that I have to put in Anssi Jaakkola and I feel Cammy Bell is better, how can I look Cammy Bell in the eye and try to motivate him three weeks later? You have to back up your players.”
Shiels linked Sergio’s dilemma with that of Fabio Capello, who resigned as England manager following showdown talks with Football Association chairman David Bernstein over the FA’s decision to go over his head and strip John Terry of the England captaincy.
“It is ironic that it coincides with the England manager not being able to pick his captain,” said Shiels. “Again, that is totally wrong. I have walked away from one job. I was asked to play a certain way while I was the manager of the Northern Ireland youth team and I walked away from the job after eight years.”