Xabi Alonso was just starting his coaching career at Real Sociedad with their B-team when he received one of the most glowing references a young manager could wish to receive, and from someone extremely well placed to make the call on his credentials.
Jose Mourinho said: 'With Xabi Alonso you always saw there was a manager there. Similarly to me, his father was a player. He grew up with a father [Periko] who was a player then a manager, and then he became a player, of course much better than I was.
'His knowledge of the game was very high. And then he played in Spain, England and Germany. And he was coached by [Pep] Guardiola at Bayern, by myself in Real Madrid, by [Carlo] Ancelotti in Real Madrid and by [Rafa] Benitez in Liverpool.
'So if you put all that together then I would say that Xabi has conditions to be a very good coach.'
Four years on, time is proving Mourinho right. After getting the Real Sociedad B team promoted to Spain's second tier, and seeing the route to the top job blocked by the success of incumbent Imanol Alguacil he shrewdly picked Bayer Leverkusen as his next stop and the team have lost only one of their last 14 games transforming themselves from relegation probables to contenders in the race for a Champions League place.
That now looks beyond them via the domestic route but win the Europa League and it's where they will find themselves next season. All Alonso has to do is get past his old mentor Mourinho.
The Roma coach loved Xabi the player. He was a soldier who carried out orders even if it meant getting deliberately sent off in a penultimate Champions League group game so as to miss a dead rubber last match, as he did along with Sergio Ramos in 2010.
The European adventure they shared at Madrid was full of heartbreak as the club fell at the semi-final hurdle three consecutive seasons. This was at a time when the club was still yearning for the famous 'Decima' its tenth European Cup.
Alonso played in 2011 when Real Madrid faced Barcelona in the semi-final.
Mourinho's game plan was to hold Barcelona to a goalless draw at the Bernabeu and beat the on the counter-attack at the Camp Nou in the second leg with away goals counting double.
For and hour, and despite the fact that Cristiano Ronaldo was clearly not in favour of the tactic of sitting back, the plan was working.
Then on 61 minutes Pepe was shown a straight red card for a foul on Dani Alves and against Madrid's ten men Lionel Messi scored twice in 11 minutes.
A year later it was Bayern who blocked Alonso and Mourinho's path to the final.
A late Mario Gomez goal gave Bayern a 2-1 advantage in the first leg and after the second leg ended 2-1 to Real Madrid the game went to penalties.
Alonso was the only Real Madrid player to score his kick. Ronaldo, Kaka and Ramos all missed as Madrid lost the shoot-out 3-1.
And in Mourinho's final year it was Jurgen Klopp's Dortmund who did for them. Alonso was taken off in the second half of both legs as the Germans won the first game 4-1 and Madrid the second 2-0.
Mourinho at the end of that season and has not been able to get back to a Champions League final since.
Alonso was a winner 12 months later with Ancelotti although he was in his suit in the stands in the final because of suspension.
Ancelotti was a breath of fresh air for the Madrid dressing room after three very intense seasons under Mourinho but Alonso was not one of those so tired of the Portuguese that he celebrated his departure.
He learned plenty from the now 60-year-old and was determined to use the experience in his own coaching career.
Mourinho's capacity to keep players switched on for an entire season, the depth of his preparation and the clarity of his instructions all made a lasting impact. As did the style of football.
It's an efficient counter-attacking football grounded in solid defending that has transformed Bayer's season under the 41-year-old, Alonso.
The BayArena is a regular 30,000 sell-out these days and it took just 90 minutes for the second leg tickets to be snapped up.
Xabi's team are the last German side left in Europe and as with Mourinho at Porto there is a sense that he wants to achieve something there before he moves on.
There is no shortage of suitors. Tottenham have been linked and back in Spain Real Madrid president, Florentino Perez is a big fan and sees Alonso as a future head coach at the club.
Alonso has gone on the record as saying his full focus is on Bayer not just for what is left of this season but also going into next season.
If Alonso comes out on top in this battle and Bayer win the final then he will be in the Champions League next season.
Mourinho might still be waiting for him there even if Roma are not because despite his comments in the pre-match press conference, PSG are serious about making him their new coach.
With two decades between them it feels as though Thursday night's meeting is the first between Xabi the coach and Mourinho the manager – but it will not be the last.