Northampton coach Alan Gaffney has suggested George North did not want to play in their defeat by Sale.
North, 25, is part of Wales' Six Nations squad but can play for Saints during the tournament's fallow weeks.
The Welsh Rugby Union (WRU) have an agreement with the Welsh regions over which players are released during rest weekends but there is no such agreement with English Premiership clubs.
"I'm just disappointed he wasn't here," Gaffney told BBC Radio Northampton.
Asked if North did not want to play a part in their 34-25 defeat, technical coaching consultant Gaffney said: "That's a very difficult question to answer for me. I haven't spoken to George personally.
"In one sense it's probably best to ask George. We picked a side that actually wanted to be out on the pitch and picked the best side for the game for Northampton."
North missed Wales' opening 2018 Six Nations win against Scotland but has played in their two games that followed, including their losses to England and Ireland.
After joining Saints from Welsh region Scarlets in 2013, North will return to Wales from next season after signing a National Dual Contract (NDC) in November.
Source: BBC Rugby Union News