Few would disagree with the view that Julen Lopetegui failed dismally to get the most out of his resources at Real Madrid.
Certainly, the Camp Nou capitulation that cost him his job last October was embarrassing, and cast in an even more unfavourable light by last week's impressive Copa del Rey draw at Barcelona under his successor Santiago Solari, who has also taken the Blancos from ninth in La Liga to second.
Nonetheless, Lopetegui's father, Jose Antonio, raised a valid point when blaming Real's decision to sell Cristiano Ronaldo to Juventus last summer for his son's struggles at the Santiago Bernabeu.
"Cristiano Ronaldo was good,” he sarcastically stated. "Was he cocky? We all have defects, but it turns out he scored 50 goals a season!
"He is missing. They are missing a prominent goalscorer. They haven't bought one, not a single one.
"There was talk of Neymar and others, but no one came. They stole 50 goals from my son!"
The language may have been emotional but the numbers were founded in fact.
Ronaldo averaged 50 goals a season during his nine-year stay in the Spanish capital, racking up 450 in total, 105 of which came in the Champions League (in just 101 games!).
The prolific Portuguese is still sorely missed.
Granted, Vinicius Junior has been a wonderfully exciting addition to the squad and a key component in Real's recent resurgence, but Karim Benzema is the only Madrid player to have hit double figures in La Liga this season – and even then, the Frenchman only has 10 goals to his name.
Of course, during his last couple of seasons in the Spanish capital, Ronaldo often reserved his best form for the Champions League and it is in Europe that Madrid are now likely to really feel the forward's exit.
The defending champions finished top of a desperately weak group but were beaten home and away by CSKA Moscow, while seven of their 12 goals came against Viktoria Plzen.
While Real are undoubtedly starting to resemble their old selves domestically – Saturday's win at Atletico was their fifth in a row in La Liga – the true test of their transformation has now arrived, with this week's commencement of the Champions League's last-16 ties.
It was in the knockout stage of the game's most prestigious tournament that Ronaldo really underlined his worth to Real.
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He was the decisive factor in the Blancos winning four of the past five Champions Leagues.
Ronaldo has a record 60 goals in the knockout stage – Lionel Messi is a distant second, with 20 fewer – and 50 of those came at Madrid.
When the Blancos triumphed in 2014, he netted eight times in the knockout stage, including once in the final, against Atletico.
Two years later, there were five knockout goals on Real's run to another Madrid derby decider, including a stunning second-leg hat-trick at the Bernabeu that earned his side a dramatic 3-2 aggregate win over Wolfsburg in the quarters.
In 2017, Ronaldo racked up an astounding 10 goals in just seven matches between the last 16 and the final.
After being shut out by Napoli in the last 16, he scored five of Real's six goals in their quarter-final tie with Bayern Munich, bagging a double in Bavaria before helping himself to a hat-trick at the Bernabeu.
Ronaldo then effectively secured his side's place in the final with another treble in his very next European outing, this time in the first-leg meeting with Atletico in the semis.
Juve were then put to the sword in Cardiff, with Ronaldo on target twice in a 4-1 win that saw Real become the first side to retain the Champions League title.
He failed to find the net in either the final or the semis last season but still plundered six goals, with his overhead kick in Turin one of the abiding memories of Real's historic three-in-a-row triumph.
In total, Real have scored 112 goals in the knockout stage since Ronaldo joined from Manchester United in 2009. He is responsible for just under half of that haul (44.8 per cent).
It would, therefore, be ridiculous to suggest that Real's chances of a fourth successive triumph have not been seriously diminished by his departure.
We have already seen the flip side of 'the Ronaldo effect' at the Bernabeu in La Liga, with Real still six points behind leaders Barcelona in spite of their fine form of late.
As Fabio Capello recently argued, "They are paying the price for thinking that they could get results without Cristiano Ronaldo."
A revitalised Real may well see off a struggling Ajax in the last 16 but Ronaldo's sale could easily end up costing the Blancos their European crown.