The 44-year-old singer songwriter has admitted he was ''disappointed'' when his colleague of 23 years made the decision to leave the group last year, although he has revealed a weight was lifted because he had noticed Tom wasn't happy performing anymore.
Speaking about the departure to The Sun newspaper, he said: ''It was a relief when Tom decided he didn't want to be in the band.
''It had been obvious for years he wasn't happy in Blink.
''For years we'd always said - well, at least Travis (Barker) and I had - Blink is our main priority. We all do other things but Blink comes first.
''We had planned to do new recordings for months but days before we were to start, Tom's manager emailed us and said he wasn't interested.
He was out.''
And Mark has revealed it was Tom's lack of interest in the band, and his fascination with space, which angered his pop punk band.
He explained: ''Of course we were disappointed and angry but then, after a while, it made sense because he just wasn't happy doing it.''
Meanwhile the 'Bored To Death' hitmaker's drummer, Travis Barker, believes the band have a ''new energy'' since they recruited Matt Skiba.
He said: ''There's a new energy in the band.''