Hearts' assistant boss will take charge of the team while the board look for a permanent successor
Hearts interim manager Austin MacPhee described the main feelings at their training ground as "shock" and "guilt" following the sacking of Craig Levein.
MacPhee will take charge for Sunday's Betfred Cup semi-final against Rangers after defeat by St Johnstone proved Levein's final game in charge.
When asked for his reaction, MacPhee said: "Shock, to be honest. The timing of it, even in the media people saw the semi-final as a crucial game if we hadn't won in midweek."
On the players, he added: "I think in any situation like this the first thing they feel is guilt. All of us do. It's the byproduct of everybody in the organisation not performing at the levels they should be.
"That was articulated this morning and, for the supporters, we now need to turn that into something positive and make sure the team put in a performance that shows what the players who are available are capable of."