Ahead of the start of 2023-24, the hope had been that the midfielder would secure regular game time at fellow Premier League side Nottingham Forest.
Instead, a disastrous stint in the East Midlands which featured less than 100 minutes of football resulted in a mid-season switch to Strasbourg, also owned by Todd Boehly and Clearlake Capital.
Santos proved to be a revelation in Ligue 1, significantly improving Strasbourg during his 11 outings and earning a young player of the month award in France's top flight.
Towards the end of his temporary spell at Le Racing, the 20-year-old spoke highly of his time at the club, acknowledging that he would be happy to return in the future.
Such a move has since materialised, Chelsea announcing on Friday morning that the Brazil international would leave the pre-season tour of the United States to start his second stint at Stade de la Meinau.
Is there a buy clause?
Although neither club have stated whether a buy clause is included in the deal, the general consensus is that it will be a straight loan.
Widespread reports have indicated that Chelsea have high hopes for Santos and plan to reintegrate him back into the senior ranks at Stamford Bridge ahead of 2025-26.
Former Hull City boss Liam Rosenior has recently been appointed as Strasbourg's new head coach due to the similarities that his style of play has with Enzo Maresca's.
Chelsea's hierarchy hope that will only benefit ex-Vasco Da Gama starlet ahead of returning to West London at the end of the season.
The first of many loans?
Even without numerous players who reached the latter stages of Euro 2024 and the Copa America with their respective nations, Maresca was able to take a 28-player squad to the United States.
Several players were also kept out of the group, and a mass exodus is expected to occur over the next four weeks as Chelsea look to find suitable temporary homes for their prospects.
Santos's loan exit is the first of a maximum of six foreign loans that can be facilitated with the recruitment team facing a complex process to determine which youngsters go abroad and who remains on the domestic scene.