Midfielder Lallana missed Tuesday’s defeat to Arsenal due to a groin issue, while forward Welbeck was an unused substitute because of a knee problem.
Striker Aaron Connolly (groin) will also be assessed but full-back Tariq Lamptey (hamstring) and midfielder Steven Alzate (illness) remain sidelined.
Leander Dendoncker and Willy Boly remain doubts for the trip to the south coast.
The pair have missed the last three games, including the 1-0 defeat at Manchester United, after picking up injuries in Wolves’ win over Chelsea two weeks ago.
Raul Jimenez remains a long-term absentee after fracturing his skull in November while Jonny (knee) is still sidelined.
Kick off at the Amex is at 5.30 on Saturday.