How exactly they got there seems worthy of further investigation.
On the face of it, the explanation seems simple enough: both are embarking upon work towards their Uefa B licences with the Scottish Football Association, the latest manifestation of a well-worn connection between the SFA's coaching seminars in the North Ayrshire town and the Portuguese game. This was first consummated by a certain Jose Mourinho, then carried on by the so-called Special One's assistant Andres Villas-Boas and countless others such as Pedro Caixinha, now of Santos Laguna in Mexico.
As might have been expected, Mourinho - who guided Costinha and Maniche to victory over Celtic as Porto lifted the Uefa Cup in Seville in 2003 and followed that up with a Champions League triumph 12 months later - was personally involved, passing on his approval as the duo made a recent whistlestop tour of Stamford Bridge.
But it is more complicated than that. Despite their illustrious playing careers, the pair's time as manager and assistant at first Beira-Mar and then Pacos de Ferreira hasn't exactly gone to plan. Their lack of the requisite coaching credentials, not to mention their habit of following each other around the globe - they also played together at Dynamo Moscow and Atletico Madrid - was quickly becoming something of a sore point.
So when the Portuguese FA dallied about organising their own coaching courses, the emergency call went not to Mourinho, but to John Collins, a long-time friend of Costinha's since their days sharing a midfield in Monaco, not to mention part of a potential coaching dream team with Ronny Deila at Celtic.
Costinha said: "I spoke to John Collins and asked him if it was possible for us to come to Scotland and coach. I visited Claude Puel at Nice, who was my coach at Monaco. And of course I went to Chelsea because he [Mourinho] was one of the coaches who put more pressure on me to become a coach. It is for him that I became a coach.
"I sent in the application, I was lucky enough to be accepted and I feel very happy to be here. We have the experience on the field but we need to have some theory, about things like injuries, physical preparation, why you pass from one exercise to another, why you do this or that. Here they don't spend expensive words explaining things to you, they talk to you like a sports guy.
"We know the people are fantastic here. We looked for information on the course because we didn't want to come in here blind. We knew that Jim Fleeting was enthusiastic. He likes to work, he likes to joke also, because that can sometimes make you become more open.
"Although you might have ideas, you can be shy, you don't know anybody, or it is difficult to understand the language. The Scottish accent is tough. But everyone is making us feel very comfortable and that is very important."
AS fate would have it, we find these august members of Portugal's so-called golden generation on this picturesque stretch of coastline just as Portugal prepare to tackle a World Cup group which includes Germany, Ghana and the USA, with matches to be played almost exclusively in Brazil's sweltering tropical north.
Both men, part of the team featuring Cristiano Ronaldo that finished runners-up on home soil at the 2004 European Championship, then fourth in the 2006 World Cup in Germany (Costinha also finished fourth at Euro 2000), are rather concerned about how reliant Paulo Bento's side appear to be on their Real Madrid talisman, especially as he is suffering from tendonitis in his knee. "At this moment the national team is around 70% about Ronaldo," Maniche said.
"So if he is not in top condition, we suffer a bit. Everything is focused on him. If he's good then everyone has hope. If he's not then everyone starts to lose the belief. Of course it's a problem when we have one of the best players in the world who is not in the best of condition.
"But this is also a chance for the group to help him because he helps the group all the time. He delivered against Ireland when we were losing 2-0 and scored four goals; against Sweden he did everything.
"He's a winner. He's very competitive. He will not let this competition pass by. So even if he is only 70% he is going to give it a go. For him it would be fantastic if he can win an important title and be champion of the world."
There is a consensus that the heat will only help the South American sides, but both men reckon the winners will come from among the usual suspects of Brazil, Spain, Germany and Argentina. Chile are the most likely outsiders.
"We have quality players in our squad who play in top leagues for top clubs all around the world," Maniche said. "But we have seen that Ghana also have good players.
"Sometimes they can have a lack of concentration at the back but from midfield to attack they are skilful, fast and strong. The United States? You never know what can happen with them. In 2002 we played against them and thought we were going to win. At half-time it was 3-0 to them. They beat us 3-2. As for Germany, it's like Gary Lineker - it's 11 v 11 and Germany always wins! They are always tough to beat even when they play badly. That's why they are one of the contenders."
FOR all their international exploits, thoughts of that 3-2 extra-time win in Seville in 2003 are rarely too far away. While Maniche savours the scoring pass for the clinching third goal, for personal reasons Costinha will always give it precedence over their Champions League win 12 months later.
"It's so easy to speak about it," Costinha said. "If you speak to almost everyone who was part of that team, it was the best year for all of us. We played beautiful football, and we celebrated that victory against Celtic more than winning the Champions League. Can you imagine that? I don't know if it's because it was the first one, or because of the way we did it.
"Arriving for the final against Celtic, it was great because we were playing in front of one of the best supports in the world. Celtic's fans, and Scottish fans in general, are well known. The atmosphere in the stadium was unbelievable. Also their team was good, strong. The way they came back into the game meant you also had passion, emotion.
"Against Monaco, everyone just expected us to win. But against Celtic, that final was different. I only played nine minutes because [Alan] Thompson kneed me in the thigh which kept me out for three months. At the end of the game Mourinho came to me and asked 'you are sad?' I said 'of course I'm sad, I won't tell you I'm happy. I'm happy because the team won the trophy but every player wants to play the final. Nine minutes? Come on…'
"He kind of shrugged and said 'Don't worry, we'll do it next year'. And I'm saying 'Oh, next year? Against Barcelona and Real Madrid and Man United in the Champions League?'. But we did."
Even the few Celtic and Manchester United fans with long memories they have met - Costinha's famous goal at Old Trafford knocked United out of the Champions League in 2004 - haven't been able to puncture the mood. "They are not giving us too much of a hard time," said Costinha with a smile.