Rudiger and Christensen are answers to Chelsea's central defence problems
The international break will have given Chelsea manager Antonio Conte plenty of time to plan ahead.
Short-term concerns over the injuries to key players -- striker Alvaro Morata and midfielder N'Golo Kante -- will perhaps have dominated Conte's train of thought in respect of team selection, but any associated stress will surely have been mitigated by the positive developments with the future Blues central defence.
Summer signing Antonio Rudiger, 24, who joined from Serie A side Roma, and 21-year-old Andreas Christensen who signed for Chelsea from Brondy as a 15-year-old and worked his way into the Blues' first team via the London club's academy sides and an impressive two-year loan spell with Bundesliga outfit Borussia Monchengladbach have both impressed when given their chances by Conte.
Somewhat bizarrely, opportunities for the duo to feature in Chelsea's Premier League games have beckoned largely because of the ill-discipline of two elder statesmen of the Stamford Bridge dressing room: 31-year-old club captain Gary Cahill and 30-year-old David Luiz. Both players have received three-match bans as a result of straight red-card offences, Cahill in the season opener against Burnley and Luiz a month later against Arsenal.
Rudiger has started six of Chelsea's seven Premier League matches at right centre-back while Christensen, deployed as the central ball-playing hub of the Blues' back three, has started three top-flight games and featured off the bench in three more.
There can be no doubting the quality of both players who are already fully-fledged internationals for their respective countries. Rudiger already has 20 Germany caps to his name and scored his first goal for Die Mannschaft in Sunday's 5-1 thrashing of Azerbaijan in their final World Cup qualifier. On the same evening, Christensen won his 13th cap playing for Denmark in a 1-1 draw with Romania which sealed a playoff place. With the Danes seeded in the draw, there's a good chance that Christensen will be joining club teammate Rudiger in Russia for the finals of the tournament next June.
Prior to the start of the season, a procession of Chelsea managers dating back to Carlo Ancelotti had made their centre-back picks from a pool of players which principally included John Terry, Branislav Ivanovic, Alex, Luiz, Cahill, Kurt Zouma and Cesar Azpilicueta. Over time as Ancelotti was succeeded first by Andre Villas-Boas then Roberto Di Matteo, Rafa Benitez, Jose Mourinho, Guus Hiddink and current manager Conte, the Blues have dispensed with the services of Alex, Ivanovic and Terry and seen Zouma succumb to a knee injury in February 2016 which sidelined the France international for a year.
The lack of longevity of service of Chelsea managers in recent years hasn't assisted matters when it comes to team succession-planning, particularly in respect of what has been an ageing Blues backline. Regardless if Conte lasts beyond the current terms of his new two-year contract it does appear that things are falling into place from a central defensive perspective.
Cahill and Luiz may well continue to play a significant part for Chelsea during the remainder of this season, but Rudiger and Christensen are well on their way to becoming established first-team stars. Zouma, completing his rehabilitation with a loan season at Stoke City, is earning rave reviews for his performances for Mark Hughes' side. It's worth remembering that prior to the cruciate knee ligament injury he sustained, the 22-year-old Zouma, who signed for Chelsea in a £12 million deal from Ligue 1 side St Etienne in January 2014, had displaced Cahill from Mourinho's first team and continued to be favoured by Guus Hiddink who took temporary charge of the Blues following the Special One's dismissal in December 2015.
Whether or not Zouma returns to Chelsea's first team next season or at some point beyond remains to be seen. The fact the centre-back recently signed a long-term six-year contract suggests the club are keen to retain his services. Zouma hadn't returned to full fitness at the time Conte revolutionised Chelsea's defence by shifting to a back three early last season and it was versatile Spain international Cesar Azpilicueta whom the Blues boss entrusted to form a partnership with Cahill and Luiz. The trio proved themselves sufficiently bulletproof to see off veteran duo Ivanovic and Terry and with Rudiger and Christensen now set to edge out Cahill and Luiz, and Azpilicueta always looking more potent when deployed as a wing-back, it will be interesting to see if Conte brings Zouma into the fold when his loan spell ends.
Should he elect to do so, Chelsea would have a youthful yet experienced backline which would serve the club well for a significant period of time, certainly beyond Conte's stay as manager. Stability at the back has always been the bedrock of success for the Blues and it will be greatly encouraging for the club's supporters that defensively at least the future looks very secure.
Mark Worrall is one of ESPN FC's Chelsea bloggers. You can follow him on Twitter: @gate17marco