“We had been hoping – the fanbase, all of us – that we could turn this around, but it became evident to me, and to others, at the weekend that we just weren’t seeing signs of it turning around,” McKinlay said.
“I went into these two fixtures, St Mirren and Ross County, feeling that we needed, at the very least, four points and hopefully six.
“Having said that, if we lost 2-1 at the weekend but had a second-half performance that was unlucky or really spirited, or we just didn’t get the rub of the green, then that might’ve made me think slightly differently, but we didn’t.
“We had a very average second-half performance and that, unfortunately, left me in no doubt that we had to look at making a change.”
McKinlay addressed the suggestion that recent two-year contracts handed to Naismith and his assistants now seemed “ridiculous and made us look foolish”.
However, he said they felt it only right that the club exercised the option, after the side finished third last season, “to give them the stability that they had asked for”.
Of B-team boss Fox, McKinlay said: “He has experience managing a team at Premiership level so I think he’s the right person for this interim period.
“He is also aware that we are looking externally for the longer term and he fully understands that and appreciates the reasons why we’re doing that.”
As for the timeline for a new appointment, McKinlay suggested it “is a difficult one”.
Although Hearts “update and refresh on a two or three-monthly basis” their list of potential new managers, they had nobody lined up as a replacement.
“Where we are now is that we’ve had our own lists and we’re also working with an analytics company,” he said, pointing out that candidates had been putting their names forward and “we’ve had a significant amount in the last 48 hours”.
“In fact, we’ve had a significant amount in the weeks previous to that, such is the nature of football.”
Meanwhile, McKinlay added that sporting director Joe Savage had left this summer “because he wanted some time away from the game, which I totally understood and respected”.
Replacement Graeme Jones, currently working his notice with the Scottish FA, will have a slightly different job as the analytics company will play a role in future recruitment.