The Woking-based team unveiled the innovative concept before the start of the season - with the design believed to increase downforce at low speed and reduce drag at high speed.
Others teams have not been convinced of their benefit, however, and believe that the blockers actually increase drag, which can have knock-on effect in terms of fuel efficiency.
Gary Anderson explains McLaren's suspension
With McLaren struggling with a lack of downforce this season, the team elected to double-check the benefits of the blockers during the post-Bahrain GP test.
It tried out its car without them, prompting suggestions that the team could be set to ditch the idea completely.
But racing director Eric Boullier has made it clear that the test was purely about double-checking its data, and ensuring that the blockers were actually delivering a benefit.
"Obviously until you have a clear correlation between your simulator, windtunnel and track, you want to make sure you validate everything," said Boullier, when asked by AUTOSPORT about why the team tested without the blockers in Bahrain.
"It was a back-to-back test for us to make sure the correlation is good. It is something we have been investigating over the winter.
"We are using other windtunnels so that is why we wanted to make sure there was no deviation.
"When you are looking for some solutions and some guidance and a way to go, you don't want to leave any rocks unturned."
Boullier revealed that the data from the test had been encouraging and left the team convinced about the benefits of the blockers.
"We are happy with this," he explained. "In terms of downforce and drag numbers, it has been now validated, so we are now happy to carry on with this.
"The car has been developed around this device so we have to keep developing the car as it is now."
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