Midfielder Cole Skuse says the Ipswich team are "devastated" for Luke Hyam after he suffered his second long-term knee injury in a year.
The 23-year-old midfielder is set for four months out after surgery, having missed the second half of 2014-15.
"It's come out of nowhere. He said: 'I've taken a kick on the knee, is it all right if I sit down?'," said Skuse.
"Next minute he's saying he's got to go back and have surgery and the lads were absolutely devastated for him."
Skuse added to BBC Radio Suffolk: "He's worked so hard, he's such a fit boy and an honest pro - it's hit everyone hard. He's a big loss, he's a very underrated player for us."
Hyam, who came through the youth ranks at Portman Road, injured himself during the club's pre-season training camp in Ireland.
Town kicked off their tour with a 6-0 win over Shelbourne, in which manager Mick McCarthy handed a debut to on-loan Arsenal winger Ainsley Maitland-Niles.
And Skuse said he was impressed by the England youth international.
"I can't believe he's only 17. He's a great lad, he's such a hard worker," said Skuse.
"For all his flair, he's got such a great workrate. That will go down an absolute storm with the manager.