The ASB Classic has lost another top player, with defending champion Roberto Bautista-Agut pulling out of the event due to fatigue.
His withdrawal follows that of Tomas Berdych, which was announced on Saturday.
The world No. 24 won the Qatar Open in Doha overnight, beating Berdych in three sets in a match that lasted two hours.
Bautista-Agut is in some of the best form of his life, demonstrated by his stunning three set victory over Novak Djokovic last week in Doha. The Serbian has been almost unbeatable on hard courts over the last six months, but Bautista-Agut trumped him in a tactical masterclass.
The 30-year-old also has an outstanding record on Stanley Street. The Spanish player hasn't tasted defeat in Auckland since 2015, and claimed the trophy in 2016 and last year, with an epic final victory over Juan Martin Del Porto. Bautista-Agut also reached the semi finals here in 2014.