His cause for concern has arisen following Sebastian Pelzer's injury against Walsall last night.
With Nils-Eric Johansson suspended and Henning Berg ruled out with an Achilles injury, it was thought that Souness would give Pelzer a taste of the Premiership on Saturday.
Unfortunately for Souness, Pelzer - who joined Rovers from Kaiserslautern this summer - only managed 30 minutes of last nights game before limping off the pitch.
The German has been plagued with injury worries since he arrived at Blackburn and is said to be "bitterly disappointed" at this latest set-back.
Souness told press: "Sebastian has had no luck with injuries and will not be happy with the way things worked out."
Following last nights injury, Pelzer was replaced by James McEveley who could now be expected to play on Saturday. The game at St Mary's would be a shock debut for the 17 year old Rover.
Souness was full of praise for the youngster after the game and believes he could go on to become a future Ewood Park star.
Souness' other options would be to hand John Curtis a first-team recall or go against the grain and employ a 3-5-2 formation against Gordon Strachan's outfit.