Their first round match gets underway at 1pm and we’ve taken a look to see what the pair actually think about one another.
Do they like each other?
Williams has been on the circuit since 1992 with Selby turning professional seven years later.
But there was a dispute between the pair in 2011 during the Shanghai Open final.
Williams led the best-of-19-frames match 9-7 and was 48-5 ahead in the 17th, heading for victory.
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The Welshman was convinced that Selby fouled in escaping from a snooker, insisting he struck the pink, but referee Eirian Williams determined that the English potter had flicked a red first.
Slow-motion replays were inconclusive and there was no freeze-frame option available at the event.
Williams went on to lose the frame and the match after Selby fought back.
But despite that result in 2011 there doesn’t appear to be any bad blood between the players.
What have they said?
Following that incident in Shanghai, Williams chose to vent his frustrations towards the officials instead of Selby.
He said in the aftermath: “I was robbed. The referee made such an appalling decision.
“It was plain to see that he hit the pink. We didn’t need to play it back. We should get Stevie Wonder to referee next time.”
Fast forward to the present and Selby has had somewhat of quiet season so far.
And heading into the Masters this Sunday he was quite keen to avoid a clash with the Welshman on account of his form.
Selby said: “Mark was one of the players I wanted to avoid in the draw because he has been playing well.
“We had a great match in the first round last year and I’m sure it will be the same this time.”
Head to head?
Over the years the duo have battled on the baize on 30 occasions.
Interestingly, the players are neck-in-neck with each having won 15 times which means this tie could go either way.
Their most recent clash, incidentally, was in at the Shanghai Masters with Williams getting his own back over Selby in a 5-3 win to progress to the quarter-finals.
Williams is also the player in form, having won the Northern Ireland Open in November.