Hadden views the competition as a "last opportunity" for a number of players to push for selection for this autumn's Rugby World Cup.
Scotland A entered the event for the first time last year when it was staged in North America and posted victories over England Saxons and Canada en route to the final where they lost to New Zealand Maori. In this World Cup year the tournament is being played in England.
Hadden said: "We go into this tournament with the intention of picking up some notable scalps. Our squad is a mix of youth and experience and the tournament also represents an important stepping stone back to full match fitness for a number of players whose seasons have been affected by injuries, such as Simon Webster, Craig Smith, Scott Lawson, Alasdair Dickinson, Craig Hamilton and Graeme Morrison.
"I also felt it was important to reflect on some of the very encouraging displays I've seen in the Magners League from some of our younger players, including John Barclay, Steve Swindall and Moray Low, all of whom are challenging for involvement in our World Cup squad.
"The Barclays Churchill Cup is the last opportunity for a number of players to put their hands up and impress for selection for the World Cup squad," he added.
"While some players will still be fighting for places for the World Cup in our Bank of Scotland August Tests against Ireland and South Africa at Murrayfield, others could secure a berth by delivering an outstanding performance for Scotland A over the next few weeks."
Hadden has not chosen a squad captain. Instead he will select on a game-by-game basis from the 29-strong squad, who convene at Murrayfield on Thursday.
Scotland A will face the USA at Henley RFC on Wednesday 23 May (ko 6.00pm) and England Saxons at Twickenham on Monday 28 May (ko 3.00pm) in their pool games. Finals day of the Barclays Churchill Cup is Saturday 2 June at Twickenham.
Scotland A squad
Backs: Robert Chrystie (Border Reivers), Simon Danielli (Border Reivers), Nick De Luca (Border Reivers), Thom Evans (Glasgow Warriors), Phil Godman (Edinburgh Rugby), Robbie Kydd (Northampton Saints), Rory Lamont (Glasgow Warriors), Rory Lawson (Gloucester)*, Calum MacRae (Border Reivers)*, Mark McMillan (London Wasps), Graeme Morrison (Glasgow Warriors), Gordon Ross (Castres Olympique), Simon Webster (Edinburgh Gunners)
Forwards: John Barclay (Glasgow Warriors)*, John Beattie (Glasgow Warriors)*, Alasdair Dickinson (Edinburgh Rugby)*, Bruce Douglas (Border Reivers), Iain Fullarton (Saracens), Andrew Hall (Newport Gwent Dragons), Craig Hamilton (Border Reivers), Ed Kalman (Border Reivers), Scott Lawson (Glasgow Warriors)*, Moray Low (Glasgow Warriors), Donnie Macfadyen (Glasgow Warriors), Mark Rennie (Bourgoin), Craig Smith (Edinburgh Rugby), Alasdair Strokosch (Edinburgh Rugby)*, Steve Swindall (Glasgow Warriors), Fergus Thomson (Glasgow Warriors)*
* = Member of Scottish Institute of Sport