The Durban-based side had 13 Springboks in their starting XV, including Siya Kolisi, but were outplayed in a game where their discipline was again called into question.
“Just disappointing,” Plumtree said. “We expected so much more. It’s hard to get my head around right now. We were flat at the start of the game.
“We had plenty of opportunities through scrum penalties to get into their 22 and build some scoreboard pressure, but we just didn’t turn up physically. They were really good and clinical, and put pressure on early with a couple of great tries.”
Having trailed 20-5 at halftime, the Sharks fought their way back into the contest early in the second period, before Vincent Koch received a yellow card and Makazole Mapimpi a red to hand the initiative back to the visitors.
“After halftime we looked good, scored, and I thought, ‘okay, we’re coming back’... then bang. Yellow to Vincent, then the red card to Mapimpi really killed us,” Plumtree said. “A comeback was always going to be difficult after that.”
Plumtree admits that questions need to be asked of everyone within the team after three defeats and a draw in their opening four games of the URC season.
“We’ve got to be harder on ourselves. That includes the players, coaches – everyone. We’ve all got to take a look in the mirror and come with a different mindset.
“But we have the quality - now we need the response.”
The Sharks are next in action on Saturday when they host the Welsh side Scarlets before a month-long break for the November internationals.