Centre-backs have seen their skill-set change over the years. Gone are the days of strong, physical players lumping the ball out of play. These days, managers expect their centre-backs to be graceful on the ball, read the game well, and stop attacks as and when needed.This has resulted in the emergence of the likes of John Stones, Harry Maguire and a certain Virgil van Dijk over the years. The Premier League currently faces a real shortage of top centre-backs. However, this is with the exception of arguably the best centre-back in Europe, Van Dijk.We look at the 5 best centre-backs in the Premier League this season.#5 Jack O'Connell | Sheffield UnitedJack O'Connell has been linked with LiverpoolWhen Chris Wilder's Sheffield United were promoted last season, much was made of his system; and in particular, the overlapping centre-backs.Wilder plays with three at the back. Usually it is Jack O'Connell on the left, John Egan in the middle and Chris Basham on the right. O'Connell and Basham often made overlapping runs out wide with the wing-backs tucked inside, often situated in a precise location for a cut-back if needed.This season, Wilder has continued with his three at the back system. All three defenders have been impressive, but O'Connell has stood out. The former Brentford player has been in fine form this season. The overlapping has continued, and both Basham and O'Connell have made a combined 26 key passes this season. O'Connell has been in good form defensively as well.The 26-year old has made 33 appearances in the Premier League this season, providing an assist. Strong in the air and a good passer, O'Connell has been linked with a move to Liverpool this summer.#4 Jonny Evans | Leicester CityJonny Evans in action for Leicester CityOne Leicester City centre-back has received the majority of plaudits this season; and it hasn't been Jonny Evans. Caglar Soyuncu's performances in the first half of the season resulted in him being linked with Manchester City. However, it is his partner Evans who has been more consistent across the season.A veteran defender, Evans has spent his entire footballing career in the Premier League. When he left Manchester United for West Bromwich Albion, not much was made of it. However, Evans' performances with the Baggies resulted in persistent links with Manchester City. He finally moved to Leicester City in 2018 for a fee of £3.5 million, after West Brom were relegated.#OnThisDay in 2018 - We signed Jonny Evans for £3.5M!An incredible bit of business. Absolute bargain #LCFC pic.twitter.com/aYFHrIfP1c— ComeOnLeicester.com (@Come0nLeicester) June 8, 2020A ball-playing centre-back, the 32-year old has been everpresent this season for the Foxes. He has been the calmer presence in the backline, when compared to the hot-headed Soyuncu. In 37 appearances in the Premier League this season, he averaged 2.7 tackles and interceptions per game. He also managed 4.5 clearances per game, while attempting three long balls.The Northern Ireland international is enjoying a renaissance in his career, and deservedly so.Also check out: the Premier League Winners by season