Daniel Levy has been told he must invest in the Tottenham squad further if Spurs are to challenge for major honours under Ange Postecoglou.

Postecoglou eased the pressure on his shoulders with a 5-0 demolition of Southampton on Sunday evening, with Spurs scoring all five goals in a dominant first half performance. The result was the last straw for the Saints, who sacked manager Russell Martin in the aftermath.

Injury-hit Spurs had been without a win in three in the Premier League up until Sunday night and had dropped into the bottom half of the table. The 5-0 win moved them up to tenth, but they are still some way short of where they want to be.

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Tottenham splashed out £130million on three signings in the summer - Dominic Solanke, Archie Gray and Wilson Odobert moving to the north London club. Two of those signings were teenagers though in the form of Gray and Odobert.

Lucas Bergvall had also been signed in February to join in the summer - another 18-year-old joining for £8.5million, with Yang min-hyeok - another 18-year-old - arriving next month for around £3.5million.

That £142million spend is not insignificant, but four of the five players signed are teenagers who will naturally take time to bed in. Spurs need players for the here and now.

Former goalkeeper Kasey Keller believes more investment is needed. Speaking to William Hill, he said: "You can't keep chopping and changing managers. It was only a few weeks ago that Spurs won 4-0 at Manchester City with a brilliant performance and last season Spurs started the season very well until several injuries happened.

"Right now, the inconsistency has been an issue, Spurs still suffer from injuries and replacements aren't the same. You also must look at the spending power of others in the league and Spurs had overachieved for years when others were spending more.

"Spurs have been close under [Mauricio] Pochettino, but in recent years Spurs haven't been in the mix for trophies. It does come down to investment in the team and Spurs have built a new stadium in recent years, one of the best in the country.

"They need to be given the tools now to compete by looking to recruit better players, a deeper squad of quality, so they can compete for trophies with these top teams. You do also need some luck along the way, but Spurs have the foundations to compete.

"You must have the right mindset as a club, and some can argue Spurs have just not invested right when it matters. Under Pochettino, he was overachieving and over-performing with the squad he had, regular top four finishes, Champions League finalists, this was the time to build and push on with adding more quality and keeping those top players.

"I had many dealing with Daniel [Levy] when I was at Spurs. He is a good businessman, you look what he has done for Spurs and off the pitch, the stadium is incredible. It's now time to really invest, back the manager to improve the squad."