Fernando Alonso might decide to retire rather than keep struggling with McLaren-Honda.

That is the claim of the Spaniard's former Ferrari teammate Felipe Massa.

Speaking to UOL Esporte, Massa had been asked about Alonso's move from Ferrari just as the Italian team surged back to the front of the grid.

In contrast, 33-year-old Alonso is now helping to build up the new McLaren-Honda alliance, insisting that he is enjoying the process.

"Our drivers are really committed," said team boss Eric Boullier this week. "They're world champions, they want to win again, they believe in the project, and they're pushing hard."

But Massa is not so sure Alonso has the patience to wait a long time for success.

"Alonso is not an easy person," he is quoted as saying. "He needs results.

"He has a personality of wanting only to be in front.

"This year he will endure working with the team," Massa continued, "but if next year things do not change, he could think again.

"I don't know what he would do," said the Brazilian. "Maybe he would end his career."

Massa said he expected Honda to start its McLaren collaboration more competitively, given the behind-the-scenes work that went on throughout 2014.

"But it was also clear that it would not be easy for them," he added.

"The new regulations are very complicated and it takes a bit of time, just as it did for Ferrari and Renault.

"Honda is a year behind those teams but they will improve and have a more competitive time in 2016," said Massa.