Amos injury a concern for Wales
Amos injury a concern for WalesSHARE
Versatile back Amos had to be helped off the field in Newport Gwent Dragons' defeat to Ospreys and is expected to be out for up to six weeks.
The 23-year-old played in all four of Wales' November internationals.
Warren Gatland's side begin their Six Nations campaign against Scotland in Cardiff on February 3.
"We are just waiting to see if we can rehab it without operation," Newport head coach Bernard Jackman said after the 9-22 loss to Ospreys.
"We are liasing with the Welsh medics to see what is the best course of treatment but it's a five or six-week injury, that's the pessimistic outlook. Hopefully we can get him back for the Six Nations."
News of Amos' injury was absorbed somewhat by the returns of George North (knee) and Alex Cuthbert (calf).
Both wings played as replacements this weekend for Northampton Saints and Cardiff Blues after over two months and six weeks on the sidelines respectively.