Ally McCoist, the Rangers manager, vented his frustration at the Charles Green "sideshow" and at his side's failings after a 2-1 defeat by Hearts at Ibrox in the SPFL Championship.

McCoist, who watched his side concede the winning goal seconds after they had equalised in time added on, was quietly scathing about the prospect of Green, who led the consortium that took over after financial meltdown in 2012, having any involvement in the club he left after claims of links with disgraced former owner Craig Whyte.

Green said last week he was willing to raise funds for Rangers, who are seeking investment. But McCoist said: "I thought the timing of it, again, wasn't great. It was a big day for the players and supporters, an even bigger day for Sandy Jardine's family."

This was a reference to the Govan Stand being renamed yesterday in honour of the Rangers great, who died in April.

Asked about the impact of the speculation over Green, McCoist said: "For the first time, one or two of the players actually mentioned to me about the timing of it and all that kind of stuff.

"Everyone does their level best to keep players sheltered from it and we will continue to do that, because the only thing they can have a bearing on is results on the park and that's what they have to concentrate on. Butsometimes it is just a little bit of a sideshow we can do without."

He added that it was "pretty fair" to treat Green statements with a pinch of salt and said of the prospect of working again with the former chief executive: "We'll have to have a look at that. We don't know what's happening; that's miles down the road."

He was critical of his side's defending against Hearts, saying: "I felt the two goals we lost were extremely poor, along with our failure to take the chances which would have made life a whole lot easier for us. The second goal was really, really poor defending."

Danny Wilson, the former Rangers defender, put Hearts ahead early in the second half with a header from a corner, and Osman Sow, the 24-year-old Swede, scored seconds after Nicky Law had equalised for the home side. Sow capitalised on defensive uncertainty after Darren McGregor had just come on as a substitute and was shuttling over to his right-back position when the ball was played down that area.

Robbie Neilson, the Hearts head coach, was understandably delighted. "For the first hour we rode our luck a little bit as Rangers had a few chances but we created a couple as well," he said. "When Rangers scored in the 91st minute the easiest thing would be for us to fold. I've been here before and seen it and it ends up 2-1, 3-1 or 4-1, but we turned it around to show we had the character to come back and win it."