Glasner was facing the media following his side's 2-1 defeat to Sunderland, which comes at the end of a harrowing week for Palace fans, starting with the embarrassing FA Cup exit at the hands of Macclesfield and also saw the Austrian reveal his intentions to leave at the end of the season and announce Guehi's departure to City for 20m pounds in the very same press conference.
The 51-year-old said he believes that he and his players have been "abandoned" by the Palace board.
"The players gave everything they could - look at the bench, just kids," Glasner said.
"We feel we're being abandoned, selling our captain one day before a game. No understanding of this. Yesterday I got told at 10.30am he's (Guehi) being sold, why not next week? It makes me really upset."
Guehi is the second talisman Palace have lost in the space of six months, after FA Cup final hero Eberechi Eze was sold to Arsenal after the season had already began.
He continued: "If you heart gets torn out twice a year, with Eze one day before a game in the summer. Now your captain one day before a game. I have no understanding. I've been in football almost 30 years, I've never experienced this once and now it happens twice in six or seven months.
"I think this is just where we are now.
"Yesterday at 10.30am I heard that the first time we were selling Marc. We have to deal with it, one day before a game going to Sunderland.
"We know we aren't in the best of runs. We don't have players available and we're selling our captain.
"Completely no understanding. No (other) team would do this. I've seen other teams, players play and, then, the next day they're leaving.
"But we're selling the day before?"
When pressed about whether the club's troubles might see him depart before the end of the season, Glasner added: "Crystal Palace are fine to end the season like this — with Oliver Glasner, with another manager, I don't know, I don't care."
Juventus have reportedly intensified their pursuit of Jean-Philippe Mateta as they prepare an improved offer for Crystal Palace, with the club determined to sign a new centre-forward before the transfer window closes.
Liverpool head coach Arne Slot said he fully understood the frustration of supporters after his side were held to a 1-1 draw by Burnley at Anfield, admitting the reaction at full-time was justified.
Mikel Arteta was left frustrated after Arsenal's title charge lost momentum in a goalless draw against Nottingham Forest, insisting his side were wrongly denied a decisive penalty late in the contest.
Cristian Romero admitted Tottenham are going through a "disaster moment" after their damaging 2-1 home defeat to West Ham, a result that has increased pressure on head coach Thomas Frank.
