Despite Tuesday's 2-0 victory over Barnsley, Birmingham were thrashed on Saturday which potentially highlights the need for a defensive change when playing teams away from home.

It was a demoralising defeat for the Blues. Having stayed unbeaten in the opening two fixtures, manager Pep Clotet will have been disappointed how easy it was for Forest to get through Birmingham's backline.

Marc Roberts was on one of the defenders who was worked hard at the City Ground. The 29-year-old had to do a lot of defending, he made 15 interceptions in the game on Saturday, which was seven more than both of his opening two matches - showing how heavily Clotet's side were on the back foot.

It's an impressive tally, and playing in a back three has helped cover his blushes at times when he is caught napping. This is something new that Clotet has brought in this season, he wants his side to play with three centre-backs and two wing-backs.

It has worked quite well so far, seven points from four games is probably better than most Blues supporters thought that they'd get at this stage of the season. An impressive victory against Brentford probably the highlight.

However, in order to take the side to that next level, they have to cut out heavy defeats, or being carved open when they play a side with some attacking prowess.

Against Forest, Roberts won just 50% of his defensive duels despite winning 75% of his aerial duels. Those stats in itself tell a story. The centre-back clearly struggled when the ball was on the deck and low crosses were coming into the box.

That's a clear problem within Birmingham's backline. The Championship has moved on into the modern era, and with that, more teams who take the game to the opposition get the ball on the ground and use their technical ability over physicality.

This appears to be part of the game that Roberts struggles with. A 31.6% long pass accuracy, is a poor showing and doesn't help start attacks. Make no doubt about it, if there's a battle, the defender will be up for it. However, the more technical attackers can cause him problems.

Clotet still believes in the defender, who picked up a clean sheet in the 2-0 victory over Barnsley on Tuesday night.

Jack Clarke-Salter, on loan from Chelsea, was another defensive acquisition bought in by Clotet and he would be the man to replace Roberts if he was to drop out of the team. He didn't play badly when on loan at Vitesse last season, where he made over 25 appearances for the Dutch side.

If Birmingham get thrashed again in the coming weeks, it'll be interesting to see where Roberts stands in their defence.