Stephen Frail admits Hearts face a relegation battle.
Hearts are now in tenth place, just a point above St Mirren, who defeated them 1-0 yesterday in a dour struggle at Tynecastle.
"We're in a relegation battle," Frail said after Stephen McGinn's first-half goal was enough to secure all three points for the visitors. "If we think we're too good to go down it will be even harder. If we think we're nervous now what will it be like when we're still there near the end of the season scrapping for points?
"In the space of a very few short weeks we've gone from working hard to try to get back into the top six to now being in a real dogfight. It's a massive surprise. But we're in it, and we deserve to be in it.
"Someone asked me the other day has the penny dropped in terms of the players having to work hard to get out of this. I'm not sure it has. And it better drop very quickly."
Fans shouted angrily at Anatoly Korobochka, Hearts' sporting director, and others in the directors' box. Majority shareholder Vladimir Romanov was again an absentee yesterday, but Korobochka still has the businessman's ear, and wrote in the match programme that changes would be made once the transfer window opened.
"Changes will have to be made," Frail confirmed. "I don't think we can bring anyone in until we get rid of some of the players that are clearly not doing what we need them to do. Something clearly needs to happen. It's as low as I've seen it."