The QPR loanee was blameless as the Steelmen slumped to a defeat which leaves them just four points off the bottom of the Premiership table.
“The first half was so bad,” Kelly said. “I’m embarrassed to be honest, we got what we deserved.
"We never started the game, we never played any of the game to be honest.
"It was just terrible, so bad.
"The manager told us all week how important the game was. Obviously we were hurting from last week (a 4-1 home defeat by Hamilton) but we didn’t want to take that into this week doing anything erractic or anything stupid.
"We just wanted to play this game for what it was.
"We were soft, passive, everything the manager doesn’t want us to be.
"Everything we’ve not been prior to Hamilton.
"We can't use having 17 players missing as an excuse, definitely not. It’s the same players who’ve been playing and getting results.
"It’s nothing to do with injuries. The team out there was more than good enough, I’m not saying to win, but to deliver a performance better than that.
"We were training at a much higher level all week, myself included. I’m not saying I’m different to anyone else, all 11 of us need to take a long hard look at ourselves.
"The performances against Ross County, Kilmarnock, Dundee United, Rangers, we know we’re a good team but the last two weeks have just been really, really poor.”