Lewis Hamilton believes he has to keep his racing "squeaky clean" for the rest of the Formula 1 season to avoid further grid penalties.
Hamilton's suggestion to Mercedes he take a double penalty to build up a pool of power units to see him through the season following earlier reliability troubles has come to fruition ahead of the Belgian Grand Prix
The accumulation of changes at Spa has resulted in a 30-place grid penalty.
But Hamilton also goes into the race knowing a further reprimand for a driving offence will mean another penalty as he has received two already this season - in Bahrain and Russia.
Asked whether there were further power unit changes to come, he replied: "We've already had the two, so I think that's enough.
"I know I just have to try and stay squeaky clean for the rest of the year, to not take any reprimands. I only took one last year so it's possible."
Aware of his looming grid penalty, Hamilton spent most of Friday practice focusing on long-run pace, avoiding low-fuel runs and eschewing super-soft tyres in the second session.
Mercedes is yet to decide whether Hamilton runs in Q3 or saves a set of tyres and ensure he starts the race with a free choice.
"I was just doing long runs [in practice] to try and get as close a representation as to what the race will be like and to ensure I won't be surprised by the balance," added Hamilton.
"As for qualifying, tomorrow is going to be pretty boring. Normally qualifying is something you target, something you enjoy most because you want to get up the front, but I'm not racing to get up the front.
"I honestly don't know what the programme is. I'm just trying to focus on getting the car as well prepared for the race as I can, and I'll take their lead on it.
"As far as I'm aware I'm going into qualifying to try and qualify, to try and go fastest, but if they decide different, whatever is the best option for the race is the most important for us.
"So I'll continue on my plan, which is trying to make these tyres last. Sunday is then the one when I've no idea what's going to happen."