The Brazilians were held to a goalless draw in their second-round qualifier with Angolan Girabola leaders Wiliete SC at Estadio Nacional da Tundavala on Sunday.
Goss started ahead of the injured Ronwen Williams in the first leg and is confident the current Champions League title holders will complete the job on their home turf.
Sundowns face Wiliete Loftus Versfeld in the second leg on Friday.
"I wouldn't say we're under pressure but we're obviously the defending champions," Goss said in the Citizen.
"They need to score at Loftus where I don't think we've lost a game so it's going to be difficult for them and hopefully on the day, we'll score as many goals as possible."
Goss admitted that the conditions in Angola, against a team in form, made it harder for Sundowns to play their normal game.
"It was a difficult game. They're obviously a big team here and they're top of the log in their league," Goss explained.
"The pitch also didn't help us a lot and the rain just before the game but I think we can take a 0-0 to Loftus. They let us build up but they sat back and didn't want to come and press us high.
"When we had the ball in our half, there was no pressure. Even when we went into their half, there was no pressure. It was clear from them that they will sit back and take a draw," he said.
Orlando Pirates breezed into the CAF Champions League group stage after a dominant 4-0 victory over Namibian side African Stars at the Orlando Stadium to secure a 5-0 aggregate victory.
Mamelodi Sundowns have been eliminated from the CAF Champions League by Angolan Girabola league leaders Wiliete SC on away goals.
African Stars head coach Gerald Guther says his side will "leave everything on the field," in their crucial CAF Champions League qualifier with Orlando Pirates on Friday night.
Orlando Pirates will be looking to progress to the CAF Champions League group phase when they face African Stars in their second leg clash at Orlando Amstel Arena on Friday.
