That is an understatement. It was the first league game he has missed this season and it showed.
Serge Aurier struggled to get his positioning right in terms of the balance between attack and defence - a consistent issue earlier in the campaign. Lamela didn't come in until the 70th minute in relief of Son Heung-Min, which was curious.
All of which is going to happen when you take Eriksen out of the team and replace him with Moussa Sissoko.
It was Eriksen's touch and eye for a pass that were particularly missed on the south coast.
Pochettino had discussed the value of the Dane's contributions only two days previously. To win the game we should do better and play better.More news: Iraqi court sentences to death German woman who joined ISIS
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'They are ill, yes, they stay at home in London to try to recover as soon as possible, ' said Pochettino. He said that Spurs had "made a lot of mistakes in possession", that they kept gifting Southampton the ball back and that they "needed to move the ball quicker and create more". They are an fantastic team with great players. He's one of the links between phases of play and is key in that regard.
James Ward-Prowse had scored Southampton's last three goals in all competitions but it was a Spurs defender who handed them the lead in the 15th minute. "We need to improve". "We did not create enough". But we had space in wide areas and we had a couple of chances.
Saints had deserved their lead and it won them strong backing from the home faithful.
The result means that we fall two points behind Liverpool in the race for a top-four finish and just three points ahead of sixth-placed Arsenal, potentially setting up a ferocious battle between now and the end of the season.
"It's so close between the teams in the top five or six". The Merseysiders are also now 14 league games unbeaten after a 4-3 win over league leaders Manchester City last time out.