Modise was not part of the Pirates squad on Saturday for the Soweto Derby and initial reports were that this was because he was injured.
KickOff.com has gathered that Modise has been battling with an ankle injury that he picked in the League game against Maritzburg United and he was been using injections to subdue the pain.
When Krol pulled Modise out at half-time in the 2-1 mid-week loss to Maritzburg there were also reports that it was a tactical substitution.
But indications now are that there may be more to this than meets the eye.
Krol made no secret on Saturday after the Soweto Derby that he would rather focus on players interested in playing.
This has given weight to the suggestions that there is some bad blood between the two.
"Teko was injured in the game against Maritzburg United on Wednesday but then when we arrived back on Thursday he disappeared without saying anything and didn’t come to training.
"To me, that kind of player is not interested in playing and so I have to focus on other players," says Krol.
Krol added that this was the first time that he had faced this kind of problem with Modise.
There have also been suggestions that Modise is reserving his energy for the World Cup but Krol tells KickOff.com that he knows nothing about that.