Aberdeen defender Michael Devlin is visiting a specialist in London to try to speed up his recovery from a foot tendon problem.
The 25-year-old has been out since sustaining the injury while on international duty with Scotland last month.
Devlin will miss the Ladbrokes Premiership clash with Dundee at Pittodrie on Tuesday night, as will Gary Mackay-Steven with concussion although the winger could return against Hearts at the weekend.
The 28-year-old former Dundee United winger has been sidelined since taking a head knock in the 1-0 Betfred Cup final defeat to Celtic at Hampden Park earlier in the month.
Asked about the chances of both players being back for the visit of Jim McIntyre's side, Aberdeen boss Derek McInnes said: "No chance for Tuesday.
"Mikey is down in London getting a second opinion from a specialist, to have a wee look at the injury.
"Not because we are overly-concerned about it, we maybe get some advice on how to push him on.
"I would say he is out for tomorrow and probably out for Saturday unless this specialist is really good and we get him back.
"Gary will miss tomorrow but has a chance for Saturday."
After beating St Mirren 2-1 in Paisley on Saturday, Aberdeen have three home games in succession against Dundee, Hearts and Celtic respectively.
After four games without defeat, the Taysiders lost 3-1 at Kilmarnock on Saturday and remain second bottom of the table but McInnes expects a big test.
He said: "I know they had a poor second half against Kilmarnock but I think it's clear that it is an improving Dundee team.
"Similar to when we played against St Mirren, even at this stage of the season, every three points is important to every team.
"We have an idea of how Jim's team like to play and you can see the benefit of a structure there.
"Even though they have changed their manager from Neil (McCann) to Jim, Dundee have always had good players.
"Both managers have a slightly different way of playing and obviously we have to overcome that challenge."
