It doesn't matter how electric your team looks going forward, if it's not built on solid defensive foundations then you're going to struggle to reach your ultimate goal on Football Manager 2021.
As with any edition of the game, a quality centre-back pairing could be the difference between success and failure. Now, we know what you're thinking - you can't be bothered scouring the globe for the best defender available and you just want to concentrate all of your efforts on signing a centre-forward.
Well never fear. We've saved you the bother by providing you with a list of the best centre-backs you can sign on the game, but don't be fooled into thinking we've been lazy and just listed the world's best defenders - every one of the players on our list is available at the right price.
We're good to you y'know...
It's clear that Juventus are keen to offload their injury prone centre-back, and with no agreed fee in place with his loan club Rennes, you can swoop in with an offer as low as £4m. Talent is never going to be an issue here, and if you can manage him correctly and keep him off the treatment table you've got yourself a bargain.
The former Real Madrid man's legs may be going but his reading of the game and defensive nous make him more than worth the gamble considering he won't cost you anything.
He's got a long way to go to reach his full potential and he may not make waves in the first team straight away, but for £2.2m Muller is a great prospect with plenty of time to develop.
Another young prospect who needs plenty of training and guidance, but the 18-year-old has the right mentality and the foundations are already laid for him to become a top defender.
Just at the higher end of the 'cheap' category, but it's worth stretching to £5m for the 25-year-old defender. A title winner with Dynamo Kyiv who's received international recognition, not only is Burda defensively sound he also brings a wealth of experience for someone yet to reach his peak.
When you view the Lazio centre-back's profile you'll probably expect him to cost about £20m, but those generous Italians will seal the deal for just £4m.
An absolute steal for any manager working within a tight budget. The former Celtic man won't cost you a penny, has good stats and perhaps most surprisingly is just 26 years of age! Although, you'll have to be quick - he soon attracts interest from elsewhere.
Adding an elite centre-back to your roster for a mere £3.5m is nigh-on impossible, but you can do exactly that by luring Chiellini away from the Old Lady. The Italian brings with him plenty of experience along with superb leadership qualities, and he could be a great asset to your club in terms of helping to mentor the next generation.
At 31, the Frenchman has a lot of football left in him and is available on a free transfer following his release from Lyon. The ideal solution if you're searching for a Thiago Silva to play alongside your Kurt Zouma.
The Slovakian is sidelined for two months with injury when you first start your save, but if anything that could work in your favour. Just £5m and the 24-year-old can become the rock in your team's defence.
Italy international Izzo can be snapped up for a little over his £9.5m valuation and his physical attributes combined with his stellar defensive qualities make him a great purchase.
The Frenchman is on the radar of a number of big clubs, so you'll need to act quick to secure his signature. At 19 the centre-back has plenty of maturing to do, but the basics and the physical attributes are already there.
While he may not possess one particularly outstanding quality, Mandi ticks the box in pretty much every category you want in a defender. A solid purchase.
Napoli will push you hard when it comes to negotiating over Rrahmani - and with good reason given his solid stats - but the Italians will eventually settle for a deal of around £9m.
If your defence is lacking a physical presence at its heart then look no further. Be prepared for Real Betis to squeeze as much as they can out of you, but if you stick to your guns you'll secure a top defender.
Despite being valued at £12.25m, Mancini is available for a cut-price fee of just £8m. The Italian boasts all the qualities needed to become a great defender and at just 24 years of age there's time for you to help him grow.
Far from the finished article and you won't have a chance of signing him for anywhere near his £2.9m valuation. However, a bid of around £12m will secure an exciting 20-year-old who you can help guide to the very top.
You might not associate Atalanta with defensive solidarity, but Djimsiti's attributes are a sight for sore eyes, and for just a few million more than his £10.25m valuation he's yours.
Jose Luis Palomino
One of Djimsiti's teammates who represents an equally attractive proposition. Can slot in at left-back when needed but is most comfortable in central defence and can be signed for around £14m.
Right at the top end of the 'reasonable' bracket, Denayer has become a stalwart of the Lyon backline since his move from Manchester City in 2018. At just 25 there's room for improvement, making £14m suddenly sound a fair price.
For £23m you can make your defensive worries a thing of the past by signing a quality centre-back in the prime of his career.
Leipzig will pretty much flat out refuse to negotiate over their prized centre-back, but a £41m release-clause means they'll have no option to wave goodbye to the Frenchman if your finances will stretch.
At just 24 years of age it's unbelievable to think this man still hasn't reached his peak. Pacey, powerful, dominant in the air and the mentality required to make it to the very top. He won't come cheap but could prove to be a sound investment in years to come.
Don't but put off by the Brazilian's far from convincing Premier League stint. Issues granting him a work permit will be ironed out following an appeal, and at just £23m he's a great option for anyone looking for a no-nonsense defender without having to blow your entire budget.
Don't be fooled by the £3m price tag - you're looking at well in excess of £20m before RB Salzburg will entertain your advances. If you can convince them to part with the 22-year-old, his unbelievable talent will see him slot into your team seamlessly.
Lazio will shun any offers around Luiz Felipe's £14m valuation, but a bid of £30m will secure the 23-year-old's services. Despite being sidelined for two months due to injury when you first start your save, his relatively cheap wages and incredible stats make him a must-buy.
Stefan de Vrij
We're not going to pull any punches here - if you want to land one of the best defenders on the game then you're going to have to delve deep into your club's pockets. However, Inter are willing to sell the talented Dutchman.
Another Inter man who the Nerazzurri will offload at the right price (and it's not a small price either - around £45m to be precise), but at 25 there's room for development of his already impressive qualities.
If you're planning on playing sexy football then he's not the man for you, but if you want a centre-back who, erm, knows how to defend, then step right up.
He might be valued at £20m but be prepared to pay double that if you want to secure the services of the Brazilian. A high price to pay for a defender in his early-30s, but if your board are piling the pressure on you to deliver instant silverware then he could be the answer to your prayers.