Manchester United have had a topsy-turvy season this term but they are not backing down from the challenge in the second half of the season. Goals may have been drying up in recent weeks, but their defensive resilience has increased.Manchester United are starting to click defensively under Ralf RangnickSince Ralf Rangnick arrived at Old Trafford as interim manager, Manchester United have conceded only six goals in 10 games across all competitions. In that period, they have also climbed up to fourth in the Premier League table and progressed to the fourth round of the FA Cup. This defensive discipline has come out of cohesive pressing and an increase in winning balls without giving away fouls. Several players have improved in the fine art of tackling and it is resulting in conceding fewer chances for the opposition to score.On that note, let's take a look at the five best tacklers at Manchester United right now.#5 Alex TellesManchester United v West Ham United - Premier LeagueAlex Telles is becoming increasingly important to the way Manchester United function under Rangnick this season. The Brazilian full-back joined the club back in the summer of 2020 from Porto and is starting to play a more pivotal role this term.Mozo Football@MozoFootball Alex Telles attempted more crosses (6), made more tackles (5) and won more ground duels (6) than any other player against West Ham. In great form. 11:02 AM · Jan 22, 202219417🇵🇹 Alex Telles attempted more crosses (6), made more tackles (5) and won more ground duels (6) than any other player against West Ham. In great form. 🔥 https://t.co/6e9QFudQsKLuke Shaw has appeared fatigued this season and has also had his fair share of injuries. At the same time, the manager has reverted to a three-man defense at times. These factors have led to Telles playing more minutes this season. In doing so, his defensive tenacity is also proving to be a blessing. Quite athletic and agile, the 29-year-old ace often pinches the ball away from opposition attackers when they are at full speed. His experience also allows him to play comfortably against the best of wingers without ever feeling intimidated. In total, the left-back has attempted 27 tackles this season, and has won 13 of those, garnering a near 50% success rate.Telles could play more often in the second half of the season and it might not be a surprise if he takes top spot on the list by the end of it.#4 Scott McTominayNorwich City v Manchester United - Premier LeagueScott McTominay has arguably been the best midfielder at Manchester United this season. The Scot has been bustling going forward and is also defensively aware of his primary duty of protecting the backline.Statman Dave@StatmanDave🏴󠁧󠁢󠁳󠁣󠁴󠁿 Scott McTominay has shown his box to box ability under Ralf Rangnick, making the most ball recoveries (28) under Ralf in the #PremierLeague.5:43 AM · Jan 3, 2022113781🏴󠁧󠁢󠁳󠁣󠁴󠁿💪 Scott McTominay has shown his box to box ability under Ralf Rangnick, making the most ball recoveries (28) under Ralf in the #PremierLeague. https://t.co/3bsfk9YvHGA box-to-box player, McTominay has the stamina to run up and down the pitch for the entirety of the game and his appetite has only increased under Rangnick. The German boss likes his team to continuously press the opposition and the 25-year-old ace carries this role out to a peach. He always knows when to put his leg in to win the ball and is often in the face of the opposition. His tall stature also allows him to outmuscle most players and win aerial duels comfortably. The midfielder has won 20 tackles out of the 39 he has attempted this season, leading to a 51% success rate.McTominay is only going to get better under a manager like Rangnick and his numbers are sure to increase in the coming months.