Wayne Brown faces a race to be fit for Hull City's vital Championship encounter with Queens Park Rangers on Saturday.
Hull are currently third in the table with a game in hand over the top two, and are two points behind leaders Bristol City.
Brown, who has made 37 league starts since he joined from Colchester last summer, sat out of Monday's training after suffering from a calf injury.
Hull boss Phil Brown told the Hull Daily Mail: "Wayne is feeling a bit of discomfort still but it's not a serious strain.
"It's a recurrence of the calf injury he initially suffered at Cardiff and maybe he came back a game too early.
"We'll monitor the injury as the week goes on and hopefully see him back on the training ground before the weekend."