A top BJP leader praised Mr Drabu's role in coordination between the two parties and said he was often the bridge between the Jammu and Kashmir government and the Centre over a host of issues.
"It is a setback to the alliance," the BJP leader, who spoke on the condition of anonymity, said. He also recalled that Mr Drabu played an important role in the formulation of the GST.
Mr Drabu was a key PDP pointsman in setting the contours of its alliance with the BJP in 2015.
PDP president Mehbooba Mufti on Monday dropped Mr Drabu from her council of ministers following his remarks that Kashmir was not a political issue, according to the party sources.
The chief minister wrote a letter to Governor N N Vohra, advising him to drop Mr Drabu from the council of ministers.
The development comes after Mr Drabu, speaking at an event in New Delhi on Friday, had said, "It (Jammu and Kashmir) is not a political issue as far as I can see. They have been barking up the wrong tree for the last 50 or 70 years by talking about the politics of it, that the political situation has never improved.
"We seriously need to look at in terms of how it is a society that is in search for itself," he said at the event organised by the PHD Chamber of Commerce and Industry."