Martin Whitmarsh, the McLaren-Mercedes team principal, has confirmed changes have been made to the pit crew in light of recent mistakes.
In Shanghai, Button was denied a shot at victory by a slow final change of tyres as the left wheel nut cross-threaded at the first time of asking.
A week later in Bahrain, Hamilton encountered two issues with his left-rear wheel, after the second of which Whitmarsh replaced the mechanic operating the gun for the last stop.
Whitmarsh was forced to console the man concerned after the race as he admitted he had taken the situation “very badly”.
Following an internal review of their pit-stop procedures during the recent mini-break that included last week’s test in Mugello, further alterations have been made ahead of this weekend’s Spanish Grand Prix in Barcelona.
Whitmarsh said: “We’ve looked at what we are doing and have made some changes to the team and the process and we’ll see them on Sunday in Barcelona - or you may see them on the earlier days if you are interested enough to watch pit-stop practice.
“There’s enormous pressure on the guys. At a team like McLaren you are targeting a sub three-second stop.
“It’s a huge physical challenge. If you’ve held a wheel gun it’s really heavy and it’s not an easy task.
“It’s being done on some very hot components with the eyes of hundreds of millions bearing down on your back.
“So I am always in awe of the level of the volunteers we have, but we have made some changes as you might expect following the last race.
“I wondered whether we’d have volunteers for some of the more critical elements, but I was astounded by how many guys in the team wanted to put themselves in that very challenging position.
“It reflects well on the spirit of the team. There’s since been a reasonable amount of practice and we’ll see at the weekend. I believe we’ll have good stops.”
The two errors in Bahrain resulted in Hamilton finishing eighth and losing his lead of the championship to Red Bull’s reigning champion Sebastian Vettel, who holds a four-point advantage.
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