Davies' made a lasting impact on Tour with the Lions in Australia last summer - making his mark in all three Tests - and at just 25, has already appeared 37 times for Wales.
And with next weekend's crunch clash against England at Twickenham fast approaching, Howley will keep a close eye on the centre's performance for Scarlets on Saturday.
"It is good to have a quality player back in the selection mix," said Howley. "He is a huge talent who matured particularly well with the Lions and was fantastic last year.
"He has become a senior player within our leadership group, and the combination of him and Jamie (Roberts) has flourished. Having him available would be a huge boost for Wales.
"We just hope he can prove his fitness. We just have to see how he comes through the game on Saturday.
"He played against London Irish (on February 1) and there is always going to be a feeling that you are off the pace a bit.
"He has trained extremely well since the Irish game and this is a second match for him. Hopefully, fingers crossed, he will come through very well."