Cowan (40) won the direct-entry tournament at the Westpac Indoor Bowls Stadium last year and is poised for a repeat performance. There are 51 bowlers entered for the Dunedin event.
The only North Island competitor is Mark Griffiths (Howick), who is combining the event with a South Island holiday.
The other direct entry event for the Welsh Masters is at Hastings.
Cowan is one of four Dunedin bowlers ranked in the New Zealand PBA's top 16 this winter who are playing in the tournament.
He is ranked seventh.
The top-ranked Dunedin bowler is Ken Walker, who is in third spot behind Jamie Hill (Auckland) and Kevin Robinson (Waikato).
The other top-ranked Dunedin bowlers are Robbie Thomson (10th) and Andrew McCallum (16th).
Cowan was ranked first equal with Hill in 2004 but dropped back in the standings over the next three years before coming back to form to be ranked third at the end of last season.
He moved up the ranking ladder on the back of qualifying for the Welsh Masters singles and finishing runner-up in the qualifying event for the Welsh pairs.
Cowan has regained the consistency on the draw that marked him as a player of potential when he started serious outdoor bowls 16 years ago.
Cowan qualified for the Welsh Open for the first time in 2004 but he spent three years in the wilderness before earning the right to have another crack at the lucrative British professional bowls scene last year.
Cowan beat his Fairfield club-mate and Bowls Dunedin president Robbie Thomson in last year's final 10-5, 9-5.
Walker has been the form player in PBA events this year and has already qualified for the English International open singles at Burgess Hill, Sussex, in November.
He has also qualified for the World Masters pairs at Potters Leisure Resort with former international Paul Girdler.
Girdler, who is 27th on the PBA ranking list, could meet Cowan in the semifinals.
Other bowlers to watch include Blair Barringer (Fairfield), Southland's Bevan Clark (Waikiwi), Nick Buttar (North East Valley), Shaun Scott (North East Valley), Shane Sincock (Redcliffs, Christchurch), Ross Stewart (Riverton), Dave Thomas (North East Valley) and Dave Archer (Taieri).
The best-performed women in the field are expected to be Carolyn Crawford (St Clair), Beth Brown (Taieri) and Sue Hodges (Outram).
The tournament is played using the set system and under the PBA format.
Driving is seldom used because the jack is always placed back at a pre-determined spot on the green and can work to the advantage of the other bowler. The tournament starts at the Westpac Stadium at 12.30pm on Saturday, with the final to start start at 4pm on Sunday.
