Scott Weiland Butchers 'Vasoline' Swears No Drugs Involved

4/30/2015 10:43 AM PDT

Scott Weiland -- Butchers 'Vasoline' ... Swears No Drugs Involved


Scott Weiland is adamant he was NOT high on drugs (including heroin) during a botched performance of the STP classic, "Vasoline," this week ... but admits something was off that night.  

Fans were shocked and concerned after Weiland -- who's struggled with substance abuse in the past -- belted out a flat, uninspired version of the song with a dead gaze in his eyes during a performance Tuesday in Texas with his new band The Wildabouts

We spoke with Weiland's rep who acknowledges it wasn't Scott's best work -- but says it was a "perfect storm" of Scott being tired and having a couple of drinks before the show. The rep says to make things worse, Scott's earpiece went out during the show, making it hard for him to stay on point. 

The rep says, "Good news we've overnighted him a brand new pair of earbuds and they will be there for his show in Baton Rouge tonight."