Midfielder blow but striker gets green light
Saints are hopeful that Emmanuel Mayuka will be fit for the weekend but Jack Cork and Tadanari Lee are rated doubtful.
Cork will undergo a check on the injury that forced him off in Tuesday's win over Sheffield Wednesday once the swelling has gone down.
The ex-Chelsea midfielder completed 80 minutes of his return to first team action before falling awkwardly.
Speaking after the 2-0 win over Sheffield Wednesday, assistant manager Andy Crosby explained that it was difficult to judge the seriousness of the knock in the immediate aftermath of the cup tie.
"We don't know at this moment," he explained. "We think his studs got caught in the turf a little bit so he has come off and we will assess that in the morning."
Crosby also added the reasons as to why some other faces were not involved on Tuesday night.
"Luke Shaw has been ill for the past few days and we can't risk him on the back of his illness," he revealed.
"Unfortunately Tadanari Lee has got an elbow injury which might keep him out for a week or so, whilst Emmanuel (Mayuka) got a block tackle when he nearly scored on Saturday and has hurt his ankle a little bit which isn't anything major and should be back in the next couple of days."