Defeat to Chelsea last Saturday was followed by a disappointing 1-1 Europa League draw with Slovenian side Maribor on Thursday, leaving Defoe keen to quickly turnaround what has been a difficult week.
Southampton have been on the back of some heavy defeats already this term, particularly against sides from the capital in Arsenal and West Ham.
|QUICK OFF THE MARK|
|9/2||Jermain Defoe is 9/2 with Bet365 to score first when Tottenham face Southampton on Sunday|
"I think Southampton are a good side with good players and they move the ball well," Defoe told the official club website.
"I watched them against Manchester United and although they lost that game, for the first 20, 25 minutes they were unbelievable.
"I can remember playing at St Mary's a few years ago, it’s a lovely stadium and I know it will be rocking. It will be a tough match but I can’t see why we can’t go there and get the three points."