The Eagles return to Premier League action following a lengthy break from top-flight matches, with our previous game the win over Ipswich Town last month.
Richards played the full 90 minutes in our win over Fulham, but will be forced to miss the trip to the south coast. However, he is the only fresh injury concern for the Palace manager.
Glasner said of the defender: "We will miss Chris Richards tomorrow. He is struggling a bit with his calf.
"It doesn’t look very serious, so we expect him to be available against Brighton at the weekend. But tomorrow is too early.
“Will Hughes is still banned, but all other players are fit and available.”
Hughes missed the quarter-final victory with illness, but is suspended for tomorrow's fixture at St. Mary's Stadium due to accumulation of yellow cards.
Chadi Riad and Cheick Doucouré remain long-term absentees.
Glasner also provided a short update on Jean-Philippe Mateta following his return to action against Fulham.
"JP is fine," he added. "I think we could see that he didn't have a game for four weeks, so he was a little bit out of the rhythm.
"These 60-65 minutes helped him to get back into the rhythm. Today's training he had a better one than maybe last week. It looks like he's getting back into his rhythm and that's very positive."
Match Details
Southampton v Crystal Palace
- Wednesday, 2nd April
- 19:45 BST
- Premier League
- St. Mary's Stadium
- Live audio commentary on Palace TV+.