Saints midfielder Victor Wanyama will be out for around a month after picking up a hamstring problem in Wednesday???s 1-0 third round replay win at Portman Road.
Koeman has already lost Toby Alderweireld and Morgan Schneiderlin in the last week and they join Jay Rodriguez and Sam Gallagher on a burgeoning injury list.
Maya Yoshida, Sadio Mane and Emmanuel Mayuka are also unavailable due to international commitments and Koeman feels changes need to be made to reduce the amount of matches played.
“It’s a problem with the schedule that the players have during what normally has to be a winter break,??? said the Dutchman.
“We have to play. Another replay? Come on, please, play the FA Cup with extra time and penalties. Why a replay? Another game – it’s crazy.
“You can always look to what you are doing in the training sessions and how we recover the players, but we haven’t trained in the last few weeks because we played so much.???
Eljero Elia and Jack Cork could return for Saturday???s Live clash with Newcastle and Koeman feels Shane Long has shown the versatility required to cover for injured colleagues after he scored the winner against Ipswich.
“Shane showed his quality and his confidence,” added Koeman.??”It’s not a question about his confidence, it’s that in the last few games he didn’t start in the team.
“We need everybody and we need Shane, and if Shane gets the opportunity he has to show his qualities like he did.”