Wales' Hallam Amos could miss the start of the Six Nations because of injury.
The 23-year-old wing injured his ankle in Dragons' Boxing Day loss to Cardiff Blues and could be sidelined for up to six weeks if he needs surgery.
"We're just waiting to see if we can rehab that or do we need an operation," Dragons coach Bernard Jackman said.
"We're just liaising with the Wales medics to see what's the best course of treatment. Five or six weeks is the pessimistic outlook."
Wales begin the 2018 Six Nations against Scotland in Cardiff on Saturday, 3 February and Jackman added: "Hopefully we can get him back for the Six Nations."
Amos missed most of the 2016-17 season with a shoulder injury but earned a Wales recall for the 2017 autumn series, coming off the bench in the opening game against Australia and then starting against Georgia, New Zealand and South Africa.
Jackman was speaking after Dragons lost 22-9 at home to Ospreys on New Year's Eve in the Pro14 Welsh derby.
Ospreys' British and Irish Lions back-row Dan Lydiate suffered a biceps injury in that game at Rodney Parade which is being monitored and may be another concern for Wales.
Centre Cory Allen also suffered a pectoral injury in that game to add to Ospreys' injury list.
Wales coach Warren Gatland is already without Sam Warburton and Jonathan Davies for the season, while their Lions colleague Taulupe Faletau will miss the start of the Six Nations after damaging medial knee ligaments.
Gatland is also likely to start the tournament without Scarlets lock Jake Ball, who dislocated his shoulder in the defeat by New Zealand in November.