Teenager Lukas Carey could be in line to replace him after a fourth defeat, this time at the hands of Middlesex, put them out of contention.
But Glamorgan will choose from an unchanged 13 at the Ageas Bowl as they look to steady the ship.
Hampshire are currently in fourth, one point off the qualifying places with a game in hand
"One common theme (in the competition) is the form of Colin Ingram," said Glamorgan coach Robert Croft.
"Jacques Rudolph showing some form at the top of the order, that's been good, and we've been very good with the new ball.
"But it's been inconsistent, and when you are that inconsistent, results catch up with you.
"Marchant has played in every game so far, and Lukas Carey is chomping at the bit, so we'll weigh up some options."
Glamorgan's Colin Ingram has risen to the top of the Professional Cricketers' Association most valuable player ratings for the competition, after taking 4-39 and hitting 83 in the defeat against Middlesex.
"It's nice to get a few wickets, I always enjoy being part of the game and contributing" said Ingram.
"In patches we've played really nicely and found ways to lose our way, but some young guys are learning a lot at the moment.
"Every game is an opportunity for someone to put their hand up and start something good, a few guys are looking for time in the middle and to get into good form."
Rilee Rossouw hit 156 to steer Hampshire to a four-wicket win at Somerset in their most recent game.
Rossouw is one of eight players with senior international experience in Hampshire's 14-man squad, alongside fellow South African Kyle Abbott.
James Vince, Liam Dawson and Reece Topley (England), George Bailey (Australia), Sean Ervine (Zimbabwe) and Fidel Edwards (West Indies) are all included, while Aussie all-rounder Ian Holland is added to the previous squad.
Hampshire (from): Tom Alsop, Rilee Rossouw, James Vince (capt), George Bailey, Liam Dawson, Sean Ervine, Lewis McManus, Gareth Berg, Kyle Abbott, Mason Crane, Fidel Edwards, Jimmy Adams, Ian Holland, Reece Topley.
Glamorgan (from): Jacques Rudolph (capt), David Lloyd, Will Bragg, Colin Ingram, Kiran Carlson, Chris Cooke (wk), Aneurin Donald, Craig Meschede, Marchant de Lange, Timm van der Gugten, Michael Hogan, Andrew Salter, Lukas Carey.
Glamorgan may rest South African fast bowler Marchant de Lange from Friday's One-Day Cup match away to Hampshire.