The victims, Will Rogers and Charlie McKill, current and former Dolphins, are understood to be doing "OK" and the club has rallied around them for support.
Sunshine Coast CIB officer-in-charge detective Senior Sergeant Daren Edwards said police allege the offender took hold of a beer glass and struck the two victims in the head.
The incident unfolded about 7pm on New Year's Eve.
"The victims, aged 24 and 25, received lacerations, contusions and bruising as a result of the attack," Sen-Sgt Edwards said.
The 19-year-old man was bailed under strict conditions to have no alcohol, not attend a licensed premises in Queensland and on curfew conditions.