McLaren have rebuilt Heikki Kovalainen's confidence and turned him into a Formula One driver who can push team-mate Lewis Hamilton all the way this season, according to Ron Dennis.
"Heikki is a guy who was systematically taken apart last year and we have systematically put him back together again," the McLaren boss said. "Give him three more races and he will be giving Lewis a real hard time.
"Lewis knows it and they are happy and joking about it. I hope as and when it becomes competitive between the drivers that the harmony keeps on," he added.
Kovalainen joined McLaren at the start of the year from Renault, where he was replaced by Spain's double world champion Fernando Alonso.
Alonso, who won his Formula One titles with Renault in 2005 and 2006, fell out with McLaren and British rookie Hamilton last year after an ill-fated switch to the Mercedes-powered team.
Hamilton ended the season ahead of Alonso, both losing out by a single point to Ferrari's Kimi Raikkonen in the title battle, and is top of the overall standings this year.
Kovalainen had a tough debut in 2007, his opening race in Australia panned by Renault team boss Flavio Briatore as 'rubbish'. Although he fought back to take a fine second place to Hamilton in last year's Japanese GP, the Finn struggled with a poorly handling car as Renault lost both their titles to Ferrari.
However, he has started well with McLaren, finishing fifth in the Australian season-opener and then outqualifying and beating Hamilton in Malaysia last weekend to finish third.
"It is a story about how this guy lost his motivation and was misguided in how he should go about his physical preparation," said Dennis of Kovalainen's time at Renault.
"But credit to (McLaren chief executive) Martin (Whitmarsh) and the guys who analyse all of the potential candidates, going back to lesser formulae. We look for the patterns. Where was the driving skill? Who was in the best team?
"When we applied those criteria he (Kovalainen) was miles ahead of any other option," added Dennis.
"Then when we spoke to him you could just see that look which says it is in there if we could just get his self-belief back, get him in a position where he knew what he had to do."