On the eve of the game, Mourinho claimed he was "deeply hurt" whenever he was unable to select a player but afterwards suggested he would be less inclined to rotate his squad in future.
For Dele Alli, Mourinho's rhetoric felt particularly ominous.
The Spurs manager made nine changes from Monday's win over Burnley but had seen enough after just 45 minutes in Belgium, making a quadruple half-time change, with Alli among the players hooked.
"Before matches you [the media] always ask me why this player is not playing, why that player is not selected," Mourinho said afterwards.
"Maybe now for a few weeks you don't ask me that because you have the answer."
The evening felt like another hammer blow to Alli's hopes of forcing his way back into Mourinho's plans and perhaps a significant milestone in an eventual departure from Spurs.
Speaking to the BT Sport studio before kick-off, Mourinho challenged Alli and Steven Bergwijn – neither of whom travelled to Burnley – to grasp the opportunity "with both hands" but clearly neither met their manager's standards.
Bergwijn, Carlos Vinicius and Giovani Lo Celso were the other players substituted at half-time, as Spurs trailed to Lior Refaelov's 29th-minute strike, with Gareth Bale the only member of Mourinho's initial front four to survive the interval. The Welshman was eventually replaced by Harry Kane before the hour mark.
Alli was guilty of several loose passes in the final third, as Spurs' new-look front four struggled for chemistry and frequently squandered promising positions.
At one point, he failed to find Bale, who would have been through on goal with the right pass. It felt like a big opportunity wasted for both players.
Alli did, however, create a good opening for Vinicius with a clever pass but the Brazilian was thwarted by the outstanding Ritchie De Laet, who twice denied substitute Heung-min Son after the interval.
Ultimately, Alli was below-par but no worse than anyone else in white, not least Bale, and it is hard not to feel as though the 24-year-old is being dealt a tough hand.
Clearly, he does not merit a place in Spurs' best XI on current form, so Mourinho cannot be faulted for overlooking him for League matches.
Equally, though, it feels unreasonable for the Portuguese to expect the playmaker to shine during infrequent cameos in unsettled teams.
The 24-year-old was making his first start in over a month and only his third of the season, having previously lasted just 45 minutes against Everton and an hour in North Macedonia against Shkendija.
Like many of the game's best players, Alli typically takes time to build rhythm and match sharpness, so it is little wonder he looked so hesitant last night, particularly given the much-changed XI and Tottenham's general lack of synergy.
Had he played alongside Kane and Son, two players he knows intimately, rather than two new signings and Bergwijn, it might have been a difference performance altogether from the England international.
It is also worth considering the mental impact on Alli of starting the season as one of Spurs' leading players before an Autumn of transfer speculation and watching from the sidelines.
Mourinho rejected the suggestion that it was difficult for the likes of Alli and Bergwijn to be at their best in such circumstances, saying: "You have to show it.
"That's an obvious thing. That's what I want from the players, that's what I expect from the players."
The Portuguese has previously criticised Alli's attitude in training but recently claimed he had been a model professional, and has consistently challenged the playmaker to prove he is worthy of place in the XI with his performances on the pitch.
Whatever the case behind the scenes, at present it feels like Alli is not being given a fair opportunity to rise to Mourinho's public challenges. As inconsequential as last night's match was in the grand scheme of things, it could be the beginning of the end for some of Spurs' fringe players.
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