DJ

I think Tottenham's recent away from looks worse than it is.  The last three away games have seen Spurs pick up a miserly 1 point.  The point was picked up at Arsenal, in a game in which Tottenham played well with a new look back 5 defensive formation, and scoring the own goal for Arsenal.  The other two away games came at Stamford Bridge (Chelsea are beating everyone at the moment), and against a rejuvenated Manchester United team, who look to be playing at a level that we had previously been more accustomed to seeing them.  Although, it can be seen that Spurs away form has been poor previous to this, with no away wins in the last 5 Premier League games.  So, perhaps worth staying away for a win on that basis.
The away games, and lack of goals scored away; only 2 goals in those three games, one of which was a penalty, suggest that Tottenham's greatest difficulty comes in scoring goals away from home.  Again. perhaps this could be seen as a consequence of the quality of opposition faced.  Tottenham have been strong away from home defensively, conceding 4 goals in those three games, against sides who are more of a threat on their home pitch than Southampton.  The 4 goals including the own goal which has been detailed above. 
I can see a fairly low scoring event here.  Southampton rely on Austin for their goals.  The last four of Southampton's home PL games have gone under 2.5 goals. For this reason, I think that the game is likely to be an under 2.5 goals encounter and will take the odds of 1.7 with Bet365 that the game ends as such.