1. Work to do at the back
Vlad Chiriches had a nightmare and new signings Federico Fazio and Ben Davies also looked shaky in the first half, especially in the opening minutes. Both Chiriches and Fazio - an £8million capture from Sevilla - struggled to deal with the pace and strength of Demba Ba, while Davies was left exposed at left-back by Besiktas' frequent raids down the right. None of the three is likely to play against Southampton on Saturday but if Tottenham are to prosper this season, the first choices need to be pushed hard by the squad players. On the evidence of this game, that is not happening as much as head coach Mauricio Pochettino would like.
2. Ba is sorely missed
In three games against Arsenal and Tottenham this season, Demba Ba has shown enough to suggest Premier League sides missed a trick by failing to sign him from Chelsea. The forward moved to Besiktas for only £8million in the summer. Clearly, Chelsea were happier to sell him abroad than to a direct rival but they would have done so had enough money been offered. Ba would have been a useful player for Arsenal, Spurs and Liverpool, to name three. He was very impressive before the break and showed a level of speed and power that terrified the Tottenham back four. His late penalty was reward for an influential display.
3. Kane is able
Harry Kane's reputation continues to grow. Long considered a fringe player at Spurs, the England Under-21 international has quickly won the trust of Pochettino and is starting to establish himself as an important member of the squad. His goal was a beauty - a low, 25-yard arrow into the bottom-right corner - but he did plenty more impressive work. One moment in the first half, when Kane robbed holding midfielder Veli Kavlak, suggested a willingness to play the pressing game Pochettino demands. Kane can finish, is strong and has awareness of those around him - a promising combination for a 21-year-old.
4. Lloris shows his value again
There are few better goalkeepers around than Hugo Lloris. Daniel Levy receives plenty of criticism from Tottenham supporters, but he deserves credit for the deal that brought Lloris to north London from Lyon in 2012 for just £8million. The France captain was outstanding in the derby against Arsenal and he maintained that form once more in this game, which Spurs would have lost had he not been in top form. He made two excellent stops to deny Ba and two similarly superb ones to keep out Olcay Sahan. Some of Tottenham's defending in this game was desperately poor but when you have a goalkeeper this good behind them, you won't be punished as often as you should be. Indeed, it was almost surprising that he did not save Ba's spot-kick.
5. Europa League is a turn-off
Early in the season, and against opponents of a decent start, it was a surprise to see so many empty spaces around White Hart Lane, especially as there was such vociferous support for Besiktas. The official crowd was 32,000, well short of White Hart Lane's capacity of 36,230. This is not a dig at Spurs fans: fixtures are frequent and tickets expensive. It is just a shame that, by adding a group phase to this competition, European football's rulers have taken away much of the excitement that the old UEFA Cup used to hold. Instead of making it Champions League-lite, why not turn it into a straight knockout tournament?Reuse content