Out-half quandary rising for England and Wales
Fly-half debates look set to rage either side of the Severn Bridge this autumn.
Prodigiously-talented uncapped Gloucester playmaker Freddie Burns, meanwhile, continues to make a strong case for inclusion at some stage this season.
This time last year, there would have been no need for a discussion in Welsh rugby circles, given how Rhys Priestland had made the fly-half position his own.
But arguably for the first time since he broke into Warren Gatland's team 18 months ago, Priestland finds himself under considerable pressure for his place thanks to a revitalised Dan Biggar and the consistent play of James Hook.
And impressions made at the spartan Spala camp could help decide some of Howley's starting XV against opening autumn opponents Argentina on November 10.
"We will take judgments from our training sessions out in Spala," Howley said.
"No doubt, the players who go to Spala are in the box seat because of the preparation time out there.
"When players come together, the intensity of training and physicality goes up a couple of levels. We see it from the Pro12 to the Heineken Cup, and then to international rugby."
Given that Hook will miss the Poland trip because of club commitments in France with Perpignan, Howley would appear to be facing a straight choice between Priestland and Biggar.
Recent Heineken Cup performances suggest Ospreys tactician Biggar has the edge over his Scarlets rival.
"Rhys holds the shirt -- it is up to the other players to get it off him," Wales skills coach and kicking specialist Neil Jenkins said.
"I am sure Rhys might be nervous, but that is what we want, to have strength in depth and people putting pressure on the players who are in possession of the shirt.
"Dan is certainly doing that at the moment. Rhys has played exceptionally well for Wales, and we have no issues with him.
"He gives us something different in the way he plays the game, but he sees the game as we do.
"He has a great balance to his game and he knows when to run and when to kick.
"If you ask Rhys to kick the leather off the ball, which you need on occasions, he will do that for you.
"It is not his natural game because he does like to play with ball in hand.
"His all-round kicking game is excellent, but his goalkicking is just off a bit at the moment.
"It is a mixture of everything. He is practising very well, and we are looking to transfer that on to the pitch."
It is almost four years since Biggar, 23, made his Wales debut, and of a further nine appearances only five came in the starting line-up.
He did not make the Wales squad that toured Australia last summer and he has been pretty much on the outside looking in for almost two years.
Jenkins added: "Dan is outstanding at kicking goals and is one of the best in the game.
"His form has also been pretty good and he is using his attributes more than he has in the past.
"He has the size by taking people on and having a go and making breaks. He is doing a lot more in the game than perhaps he did in his earlier years."
Howley, meanwhile, also has the match-winning brilliance of Hook at his disposal, and it is inconceivable that such a gifted player will not prove influential at some point during the four-Test autumn schedule.
"James is a quality player and we know what he can do," Jenkins said. "His problem is that he is so good he is capable of playing in so many different positions.
"I am sure he would love to be able to stick in one position at outside-half and challenge for that position. I feel he is a world-class, outstanding 10 and that is his best position.
"When he has played for us there he has been very good and if you asked him his favourite position would be 10. That is where he wants to play."