Fernando Alonso set for 35-place grid penalty in Spa

SPA-FRANCORCHAMPS, Belgium -- Fernando Alonso is set for a 35-place grid penalty at the Belgian Grand Prix after his new-updated Honda power unit suffered a water leak during first practice and needed to be replaced.

McLaren fitted the updated Honda power units to both cars ahead of the first practice session, but Alonso completed just three laps before a water leak from the Energy Recovery System was discovered. A detailed investigation of the issue is set to follow, but in the meantime a completely new power unit of the same updated specification has been fitted to Alonso's car ahead of second practice.

Under the regulations, drivers are restricted to five of each power unit component per season before incurring penalties. The change means Alonso is now on his sixth of all six components, resulting in a 35-place grid drop in total.

He is likely to be joined at the back of the grid by Sauber's Marcus Ericsson, who incurred a 10-place grid drop for using his sixth turbocharger of the season during first practice, and Lewis Hamilton, who currently has a 15-place grid drop hanging over him after he took his sixth turbocharger and MGU-H this weekend.

If any of the teams decide to stockpile components this weekend so as to avoid more penalties at future races, the size of the grid drops could increase further.