Dan Fallows' aborted move from world champions Red Bull is now the subject of a legal dispute, but Peter Prodromou is definitely joining in 2015.
And AFP claims other prominent F1 aerodynamicists - Sauber's Tony Salter and Lotus' Guillaume Cattelani - have also been signed by McLaren.
"McLaren is composed of brilliant individuals, they have been winning many races and have been fighting for championships," said Boullier.
"I think it is just to make sure that the same people are working together in one way with strong leadership, strong guidance and at least it will help them to recover their past success," he added.
Now, international publications Omnicorse and Speed Week report that McLaren's 2014 car could be set for a dramatic aerodynamic turn this weekend in Barcelona.
Earlier, Williams' Pat Symonds said he suspected other teams would be looking into designing a version of the innovative asymmetrical nose at the front of the 2014 Lotus.
"Lotus have been haemorrhaging employees from all departments over the last few months, so I think all of the teams had an idea of where they were going," he said.
Italy's Omnicorse claims the solution has been in the wind tunnel at Woking for some time.
"We have also looked at several interpretations (of the double nose)," admitted Symonds, "but some of them simply did not fit with our car."