When you have your best players available, it is like a comfort blanket for the rest of the team. When Harry Kane plays for Tottenham his team-mates know that whatever happens, they have someone in attack who needs only a half-chance to score.
When players like that are injured, as Kane now is, you can find yourself hoping to win games, rather than believing you will do so. When I played with Michael Owen and Robbie Fowler at Liverpool, no matter how things were going in a game, you always believed you would score.
Make no mistake, it will give Southampton a boost. Just hearing Kane is out will have given them a little buzz. In public, players often talk about wanting to face the strongest possible opposition but this is generally not the case.
In reality, you want to have the best chance of winning the game and Tottenham are more vulnerable without Kane, their top scorer with 24 goals in all competitions.
Heung-min Son and Vincent Janssen simply don’t have Kane’s consistency, so Southampton may play with a bit more courage.
Kane is likely to be out for at least five or six weeks and if Tottenham lose form during that period, the other players will start to worry. I have been there myself.
If we were without Steven Gerrard or Owen at Liverpool, or Clint Dempsey or Mousa Dembele at Fulham, I’d find myself chasing them around, seeking them out in the treatment room to ask when they would be fit.
It is easy to get into a negative mindset and I would advise Spurs’ players to put complete trust in Kane’s replacement, whether it is Son or Janssen.
When fringe players get a run in the team, you can be guilty of worrying too much about them. Do that too often and you forget to concentrate on your own performance — which can be fatal. You have to focus on your job.
If Son is the man to replace Kane, as I expect, then Spurs will play slightly differently.
Son is slightly quicker than Kane and will run the channels a bit more often, so you are looking for different ways to release him.
If Southampton push a little further up the pitch, that could give Son more opportunities to find space behind their defence.
A sign of a strong team is the ability to take the same approach to all matches. It was one of our strengths at Fulham in the 2009-10 season, when we reached the Europa League final.
Players were rotated but because of everyone’s attitude, it felt as though we could maintain the same rhythm. Spurs need to show the same resilience.