This article is part of Football FanCast's The Chalkboard series, which provides a tactical insight into teams, players, managers, potential signings and more...

Tottenham Hotspur manager Mauricio Pochettino made a big mistake before kick-off against Watford on Saturday, and he must take the opportunity to make amends for it against Red Star Belgrade today.

On the chalkboard

The Argentine decided to leave Erik Lamela and Son Heung-min – presumably influenced by their international exertions even if the former didn't play a single minute, as well as the upcoming European encounter – on the substitutes' bench against the Hornets, playing a 3-4-2-1 formation with Dele Alli and Lucas Moura joining Harry Kane in attack.

It was a decision that failed to pay off as Abdoulaye Doucoure found the net in the sixth minute, with the hosts not managing to find an equaliser until the latter stages of the contest through Alli.

There is no doubt that Lamela and Son paid their part in that goal coming have made impressive cameos from the substitutes' bench – on 63 and 46 minutes respectively – and they must start against the Serbian outfit on Tuesday.

Why's that?

Well, despite their travels the duo were full of energy and work rate when they entered the pitch against Quique Sanchez Flores' men, and Son almost made an instant impact when he saw an effort cannon back off of the woodwork.

The South Korea international and Lamela were arguably Tottenham two best players in what was another disappointing performance and result from the north London club, and not starting them may well have cost Spurs when it came to having that intensity, passion and pressing ability in attack from the very first whistle.

That will be needed to ensure Pochettino's men don't give Red Star any confidence or hope that they can pick up a positive result on their travels, because that would be the last thing they need in their current situation.

The duo's reaction from the bench to Watford's opener shows how much they care about the welfare of the football club, and you can't afford not to have characters like that in the starting XI when times are tough, and others like Christian Eriksen and Toby Alderweireld continue to falter on the pitch with their contracts expiring next summer.

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