The Jönköping club further states that they are "working on a solution" to cover Stillman's absence.
"It is of course sad and we are trying to support Fredrik both as an employer and colleagues. At the moment it is important that Fredrik gets peace and quiet and the chance to recover. Recently, the amount of hatred and threats directed at our employees has escalated, and this is something that we as an employer take seriously," says club director Richard Nylin in a statement.
The club does not comment on whether any concrete threats against employees have been reported to the police.
Last week it was also announced that club director Nylin will leave his position on March 31.
HV71 has had a tough season and is second-to-last in the SHL, with seven points from the qualifying round.
