Last September, when last-man Christensen was sent off for an ungainly, farcical rugby tackle on Liverpool's Sadio Mane, it truly felt like the Danish defender had blown his last chance to make it at SW6.
Six months later, against Everton, a markedly more confident player breezed across the turf to seize possession from the through-on-goal Richarlison as he hurtled towards the Blues net - a moment that typified the defender's recent resurgence under Tuchel.
This fine run of form, which began with back-to-back clean sheets against the likes of Atletico Madrid, Manchester United and Liverpool, continued with stellar showings against Leeds and Sheffield United where his admirable composure once again aided the Blues in preventing their opponents from scoring.
His impressive work hasn’t gone unrewarded, either, and has seen him pick up a nomination for March's Premier League Player of the Month award.
It's hard to believe that the Blues defender is approaching a decade at Chelsea, and his slow-burning development looks like its finally on the brink of delivering the finished product.
It could have been quite a different story:
Christensen dodged a loan spell at Chelsea's very own X Factor boot camp, Vitesse, where he could have suffered the same fate as scores of young Blues before him - gradually slipping from the collective consciousness of Chelsea fans, consigned to touring the Butlins circuit in a struggling hip-hop duo with Lucas Piazon.
While there have been the notable exceptions of Nemanja Matic and shining poster boy Mason Mount emerging from a spell in the Netherlands ready to headline Glastonbury, the Blues' ‘loan army’ has generally produced players destined to feature in obscure ex-Chelsea talent trivia - Gael Kakuta, Slobodan Rajkovic et al.
Instead, Christensen, spent two strong seasons on loan with Borussia Monchengladbach - where Tuchel, then manager of Borussia Dortmund, developed a keen interest - diligently developing his game in the German top tier while his parent club marched to the Premier League title in 2017.
Upon his Chelsea return, the Denmark international made 40 appearances in the 2017/18 campaign, before Maurizio Sarri's arrival the following year saw him drop down the pecking order - that said, the 24-year-old played more minutes than any of his teammates in their Europa League-winning campaign.
Under Frank Lampard, he, like most of the Blues defence, were rotated ceaselessly and to a dizzying degree, resulting in the defence looking ragged as they searched in vain for consistency in the troubled latter days of the Chelsea legend's spell at the helm.
Of late, fortune has smiled on Christensen, with stand-out academy product Fikayo Tomori inexplicably bundled out to AC Milan on loan, Thiago Silva's ongoing injury concerns, and Tuchel's desire to play with a back-three combining to see him enjoy a first-team renaissance.
A huge opportunity now awaits the ex-Brondby youngster to prove he deserves to be a vital presence in Chelsea's back-line going forward - both literally and figuratively.
Behind Silva, Christensen is arguably Chelsea's best ball-playing defender. Kurt Zouma possesses the technical ability to masterfully arch sumptuous forty-yard passes across the field, but his close-range, forward passing lacks the urgency required to see his side efficiently switch out of defence.
Antonio Rudiger's gutsy ram raids up the field have added a fresh dimension to side's play, but his frequent heart-in-the-mouth, hospital passes will do little to halt the thinning of his manager's hair.
There is, however, an issue that can swiftly knock the needle off the ‘Ten Things I Love About Andreas Christensen Megamix’ record with a jarring scratch: the summer transfer window.
It's hard to predict just how deep Roman Abramovich will dip into his cavernous pockets to provide Tuchel with shiny new signings, but you can bet your bottom dollar there will be a sizeable war chest waiting to be cracked open and splashed with abandon on Europe's premium footballing talents.
It's common knowledge that a blockbuster central defender is among club's key targets when the window opens, and the likes of Bayern Munich powerhouse Niklas Sule, RB Leipzig starlet Ibrahima Konate and Atletico Madrid's Jose Gimenez have all been linked with big-money moves to west London.
Silva, who has added some much-needed stability to the Blues' back-line, is now in his twilight years, and any defender brought to Chelsea this summer will be done so with an eye to becoming his successor - but, the addition of another centre-back could see either Christensen or Rudiger anxiously looking over their shoulders, adding an uncertainty to their long-term futures at the club.
Rudiger, on his day, ticks the essential box of grit and relentless dynamism at the back. Sure, he's still prone to those moments of utter lunacy - the harrowing flashbulb memory of his ludicrous own-goal against Sheffield United last month serving as stark reminder - but his transformation under Tuchel has been remarkable, and he's richly deserved his continued run in the side.
In Christensen, then, Chelsea could have the third and final piece of their defensive puzzle sitting right under their nose; negating the need to blow their budget on Silva's understudy, and standing tall as an elegant ball-player who could fit snugly alongside Rudiger and, of course, criminally underrated captain Cesar Azpilicueta.
He's no snarling, tough-tackling centre-half of old, that is for sure, but the Dane does boast the technical ability necessary to thrive in the modern game, and can bring some real class to Tuchel's burgeoning Blues set-up.
Chelsea, quite famously, have prematurely parted company with an abundance of future stars in the past, but the uncharacteristic patience shown in their desire to hang onto one of their most gifted starlets could be about to pay off - if he's given the chance to flourish.