The 21-year-old defender highlighted the Royals' performance against Manchester United for inspiration, adding that the league leaders got lucky at the Madejski Stadium
Brian McDermott's side currently sit second from bottom of the Premier League with just one win from their first 14 matches, while Southampton sit one place and three points ahead of them.
Morrison feels they must close that gap in order to keep pace with the rest of the league before they start slipping away, and the 21-year-old says anything other than a win would be a bad result.
|READING TO EDGE VICTORY OVER SAINTS?|
|12/1||Reading are 12/1 with Bet365 to beat Southampton 2-1 at St Mary's|
Morrison told the Reading Chronicle: "Saturday is a massive game and some people may call it a six-pointer. We're amongst a group of teams down near the bottom and now we need to go to Southampton and pick up three points.
"It doesn't matter how we do it but that has to be our goal now."
The defender highlighted Reading's performance against league pace-setters Manchester United at the end of November, saying that the Red Devils failed to dominate proceedings and scored several lucky goals.
He continued: "If you look at Manchester United's goals, they were all fairly soft apart from maybe Robin van Persie's fourth one. It's not like we were ripped apart.
"It was disappointing but all we can do is take the positives from that into Southampton.
"We felt comfortable in our shape and in the second half they sat there and made it hard for us to break them down.
"I think we can take away a lot as they're one of the best teams in the world. But I would exchange that goal for a point or three any day of the week."