"We were having dinner and I said 'this is really irritating me' and she was like 'pull your pants down and show me, it might be shingles' and I was like 'okay'.
"And then the next day I got the doctor and she was right."
Murray's mother-in-law is Leonore Sears.
The 29-year-old looked jaded in Melbourne having had little time to recover and reset after his phenomenal end to 2016.
Five weeks and a period of enforced rest later he was back on court in Dubai.
Murray made a slow start and struggled to find his first serve but he got better as the match went on and emerged a comfortable 6-4 6-1 winner.
The first set was anything but straightforward for Murray, with 51st-ranked Jaziri playing with freedom and taking advantage of his opponent's difficulties on serve.
The Tunisian, in the best form of his career at 33, broke for 2-1 on a very fortuitous net cord but Murray hit straight back and broke serve again to win the opening set.