Yuvraj has played 250 one-day internationals for India
Middlesex are not signing Yuvraj Singh for their Twenty20 campaign after it emerged he would miss most of the competition while on tour with India.
Yuvraj, 28, was due to play for the county between 1 June to 18 July.
Middlesex chief executive Vinny Codrington said: "We had received a signed contract from Yuvraj confirming that he was playing for us."
But India's tour of Zimbabwe in May and June and the Asia Cup have now deemed Yuvraj to be unavailable.
Codrington continued: "We had received full approval from his agent as to the terms of our agreement with Yuvraj and we had received full approval from a prominent member of the Board of Control for Cricket in India.
"We had even agreed what squad number he would be sporting and what name he would be wearing on his back."
However the BCCI have now confirmed that India, along with Sri Lanka, will take part in a one-day international triangular series in Zimbabwe, as well as playing the hosts in two T20 internationals.
"That meant that Yuvraj would in all likelihood not be available for all of our five home Twenty20 matches at Lord's, which though far from ideal, we considered still worth our while bringing him over," added Codrington.
We have since been advised that Yuvraj will be required to represent India in the tri-series tournament, leaving us in an untenable position
However, the county have now received notice that Yuvraj would be required to take part in the Asia Cup, scheduled for the end of June, in addition to a pre-tournament training camp.
"Calls to the BCCI to seek clarification on this point have proved fruitless, however we have since been advised that Yuvraj will be required to represent India in this tournament, therein leaving us in an untenable position," said Codrington.
"That has lead us to make the decision to notify Yuvraj Singh's representatives that we will not be pursuing our interest in bringing him to Lord's."
Former Australia wicketkeeper Adam Gilchrist has already agreed to join Middlesex for the Twenty20 campaign, but India batsman Sachin Tendulkar rejected a move to Lord's.