Cardiff Blues director of rugby Dai Young is hoping Tomos Williams and Cory Hill are not seriously injured after coming off in the 13-10 win over Scarlets.
Williams was forced with an arm injury, while Hill suffered a hamstring problem.
Scarlets prop Wyn Jones also suffered a neck injury after only just recovered with concussion.
The trio have all been included Wayne Pivac's 36-man Six Nations squad.
Wales open their campaign against Ireland on 7 February and link up together next Monday.
"It is hard after a game but it looked like Cory twinged a hamstring and Tomos had a shoulder bump," said Young.
"We don't think it will be too bad, hopefully."
On Scarlets prop Jones, head coach Glenn Delaney added: "He is up and about and it did not look too serious so we don't think there are too many concerns around him."
Scarlets number eight Sione Kalamafoni was also forced off the field in the second-half with a head injury after receiving a stray elbow in the face from Cardiff Blues prop Dmitri Arhip.
The incident was not penalised by the match officials.
"It was not reviewed so clearly they did not see any evidence to say that it needed to be," said Delaney.
"I have had a couple of looks at it and maybe some others will have a look at it too. The key thing is that he is up and about which we are happy about after a knock to the head."
South African number eight Uzair Cassiem, who is set to leave Scarlets at the end of the season, replaced Kalamafoni.