I have had 2 in my immediate family go with a brain tumour. Mother and brother. Yes it is sad news. The irony is I never saw him play even though he was well within my era. I was in the RN back in the 70s and away from Plymouth for all of his time here. He came back as assistant manager originally during our crash into financial ruin and then managed us for a short time when the manager left. We really couldn't afford anyone and he stepped up. He was on a hiding to nothing with the players we had and I doubt anyone could have made a fist of the job let alone somebody who was a bit of a novice. The supporters did back him though given his history with the club. Many of a certain age here will say he was probably the best player they ever saw in a green shirt.
Saw him play a number of times for Pompey back in the mid to late 1980's. Very skillful striker. Sad loss at only 68. RIP Paul Mariner