Winger Niall McGinn is set to miss Aberdeen’s opening European fixtures as he recovers from ankle surgery.
The Dons are set to enter Europa League at the first qualifying round stage on Thursday July 11 with the return leg on July 18.
McGinn will be ruled out for both those ties as he continues the rehabilitation from recent surgery on ankle ligament damage.
Dons boss Derek McInnes confirmed the Northern Ireland international will not return to training until mid-July at the earliest.
McInnes also confirmed McGinn is targeting a competitive return for the beginning of August.
Should Aberdeen progress to the second qualifying round, the 31-year-old winger would also be ruled out for those ties on July 25 and August 1.
McInnes said: “The best case scenario for Niall to be back into training with us is the second or third week of July.
“Niall has a long road ahead of him but will have to get his head down and work away throughout the summer.
“Sometimes it is not until you get right into the rehabilitation that you can know if there are going to be any upsets.
“However, if everything goes according to plan then I am pretty sure Niall will be back available to play competitive football again in early August.”
That means McGinn could be battling to be match fit and sharp for the third qualifying round if the Dons were to progress to that later stage in the Europa League.
The third qualifying round is played on Thursday August 8 and Thursday August 15.
The draw for the first and second qualifying rounds will be made at the UEFA headquarters in Nyon, Switzerland, on June 18 and 19.
Aberdeen will be seeded for both rounds, which should make potential progress easier.
Last year the Dons were not seeded when entering at the second qualifying round stage and they landed English Premier League side Burnley.
The Reds lost out 4-2 on aggregate following extra-time at Turf Moor.
The absence of McGinn from the opening Euro ties is a blow to the Dons.
Boss McInnes will likely have to land a winger in the summer in time for the Euro campaign as the future of Gary Mackay- Steven remains frustratingly unresolved.
Scotland international winger Mackay-Steven is set to go out of contract with the Dons at the end of the month.
McInnes wants to retain the 28-year-old on a new contract, but Mackay-Steven has yet to make a decision on his future.
MLS side New York City are also keen to sign Mackay-Steven.
The winger confirmed following the 2-1 win at Hibs to end the season that he planned to talk through his future with his agent and family.
He refused to rule out remaining at Aberdeen as an option.
McInnes faces a busy transfer window and has already moved to secure the return of former Aberdeen defender Ash Taylor.
The centre-back, recently released by Northampton Town, was in Aberdeen for contract talks last week.
Taylor spent three seasons at Pittodrie before leaving for then-League One Northampton in summer 2017.
The defender is a free agent as the final year of his Northampton contract was recently terminated by mutual consent.
Aberdeen have also beaten Hearts to striker Curtis Main.
The Dons are close to getting a deal for the 26-year-old striker, who is out of contract with Motherwell, over the line.