Spencer talks from experience, as he started both legs when these two sides last met in the 2009 Confederations Cup second round.
After a 2-2 draw at home, Sundowns went to Kinshasa for the reverse leg and needed only to avoid defeat, or a draw that involves both teams scoring more than two goals each.
They eventually lost by a solitary goal in front of a packed Stade Tata Raphael – the venue of this afternoon’s first leg tie, which will precede the reverse leg in Tshwane in nine days time.
“Plenty of what Sundowns will deal with will be mental. In fact, 90 percent of what Sundowns will deal with will be a mental test because everything is against you from the moment you get to the airport," says Spencer.
"It is a tough time out there but they will have to try and focus on the football."
Forced into premature retirement just after his 30th birthday, the now 33-year-old still has vivid memories of what they had to endure on that visit to DR Congo seven years ago.
“It was a very difficult trip, trust me when I say so, because from the moment you land at the airport it suddenly rains on you that you are away from home," he recalls.
"Comfort suddenly becomes non-existent. The hotel that we had been booked into wasn’t up to scratch, which meant we had to find an alternative hotel to check into.
"When I look back I now get to understand how mentally testing that trip was for us. When you are in DRC you will definitely feel that you are away from home.
"You keep getting reminders that you are not at home when you are there because even the ordinary people are out to make you feel it.
"I mean, we were even made to pay more money for our bills at the hotel that we had checked into, it was hell. The thing is they are just out to frustrate you in whatever way they can."
Spencer added: “When we got to the stadium on match day it was only us players and the technical team that were allowed onto the pitch with the rest of our staff including security being restricted.
"The crowd plays a huge role as the stadium was packed to capacity. On our way to the stadium from the hotel on match day we had fans of Vita on every road that we used and they were all shouting at us, throwing stones and telling you that you are in for a hiding today.
"We were eventually escorted by soldiers to get into the stadium. On the field we did well and they scored from our mistake. However, the referee was a nightmare with everything going against us."
Despite the rough ride that he expects Sundowns to endure in the city, which is situated on the Congo River, the ex-Bidvest Wits captain feels they can get a positive result.
“Sundowns have a good team and I think they are well prepared for this. I am not too sure about the current form of Vita, but Sundowns are in encouraging form. All the best to Sundowns, I am with them in this one."
Kick-off for the clash is scheduled for 16h30 on Sunday afternoon.