Chris Clark looks to have damaged his knee and although it is too early to say, there are concerns it could be a bad one.
He will now get further tests this week to see the extent of the injury.
The incident happened early in the game when there was no one around him.
Clark missed most of last season with an ankle injury and has been working really hard to get himself fit again. The midfielder has been really impressed during pre-season in the full back spot.
With Andrew Considine still being a little bit away from being available in does leave manager Derek McInnes a bit short in defence.
Everyone is hoping the injury to Chris is not as bad as first feared.
On a slightly more positive note AFC Youth Academy product Scott McKenna started his first his game for the senior side and the 16 year old looked very impressive. The central defender only joined the Dons as a full time professional in the summer after making a few appearances for the U20 side at the end of last season when he was still at school.
As well as Scott, Derek McInnes fielded a very young Dons side and changed ten of his team that cruised past UCD on Tuesday with only Joe Shaughnessy starting again.
Nicky Weaver made his Dons debut in goal after signing on Monday night. The keeper's first act in the game was to pick a deflected shot from Shane Dunn out of the net after just three minutes. Things then got worse for the Dons when Clark was carried off soon after. He was replaced by Declan McManus.
It took the Pittodrie side until ten minutes before the break to equalise against the lower league outfit and it took an excellent drive from Jamie Masson from the edge of the box to draw them level.
Shortly after Scott Vernon headed in a superb Craig Storie cross to give Aberdeen a half time lead in the Irish coastal town. At the start of the second half Vernon then netted his second of the evening from the penalty spot after he was fouled in the box.
Vernon was unlucky not to net his hat-trick later on but headed wide from close range. At the other end Weaver made a couple of decent saves and communicated well with his defence throughout.
Nicky Low completed the scoring late on with a fantastic 25 yard drive.
Jonny Hayes, Mark Reynolds, Ryan Jack, Clark Robertson and Josh Magennis also got run-outs as the Dons were given a decent test at picturesque Gannon Park. The weather was still extremely warm and there was a number of water breaks needed to cool the players down.