Mikel Landa can come back next year and challenge Chris Froome for Tour de France victory, the current champion believes.
Landa was lying fourth at the Tour after Thursday's final mountain stage at 1min 36sec, despite working for Sky team leader Froome throughout the race, and having ridden in May's Giro d'Italia.
The 27-year-old Basque has already said he's leaving Sky at the end of the year to look for a role as a team leader, and Froome has no doubts he will come back in 2018 to challenge the Briton, who is on the brink of a fourth overall success.
"He did have a tough first week in this year's race but, keeping in mind he did the Giro d'Italia, he's come up through the race remarkably well," said Froome.
"He's really been there for me in the moments when it's been tough up there in the mountains. I'm extremely grateful for that.
"He's got the engine to ride with the best in world and he's certainly capable of coming back to contest the overall victory."
Landa has already set out his stall: he wants to be number one.
"Let's be clear about this, this can't happen to me again. I won't go back to being a number two," he told journalists on the second rest day.
In 2015 he played second fiddle to Fabio Aru at the Giro d'Italia, giving up his own aspirations to help the Italian, who finished second to Alberto Contador while Landa was third.
It was one of the reasons he then left Astana to join Sky, ostensibly to be the team leader at the Giro.
However, illness cost him and he quit the race after 10 stages when sitting eighth overall in 2015 and earlier this year, as co-leader with Geraint Thomas, a crash in stage nine ended his overall hopes, although he battled back to win the mountains jersey.
But still, his Giro woes have seen him spend two years riding as Froome's domestique in the Tour.
What Landa wants now, is an unequivocal role as team leader, wherever he can get it.
- Self-confidence -
"You have to make the right decision relating to your personal objectives," said Landa.
"I've been through that experience with Astana and it's happening again.
"Life is about the decisions you make for your own interests and the confidence you have in yourself."
Landa has a lot of self-confidence and hasn't been afraid to show his strength at this Tour, much like Froome did when riding as Bradley Wiggins's chief domestique in 2012.
While Wiggins seemed to be annoyed by questions about whether or not Froome could beat him if given free reign, the latter has spent much time praising his Basque team-mate this year and repeatedly thanking him for his efforts.
"Mikel Landa has been a brilliant team-mate, absolutely amazing," he said on Wednesday.
"He's getting stronger and stronger the further into the race we go.
"He has the potential to finish on the podium."
When Landa leaves at the end of the year, it won't be the first time Froome has lost a key team-mate with lofty personal ambitions.
Rigoberto Uran had ridden for Froome in the 2012 Vuelta a Espana before leaving at the end of 2013 to pursue his own Grand Tour ambitions.
He finished runner-up at the Giro dItalia in 2013 and 2014 and is now set for a podium finish at the Tour.
Richie Porte was a key help to Froome in his 2013 and 2015 Tour victories but grew tired of waiting for his own chance, especially after his bid for Giro glory in 2015 ended early after a crash.
He was expected to be Froome's biggest rival this year but again crashed out.
Once again, next year, Froome is likely to line up against a former lieutenant, now hell bent on taking his title.
And Landa could be the man to finally manage that.