The squad leave for the first of two separate week-long training camps in Poland on Saturday with the full list of personnel attending to be announced on Friday.
Stoddart will remain in Wales for treatment but the Scarlets flier is expected to be available for the second camp which takes place the week beginning Monday July 18.
"Morgan has picked up a strain to the quad muscle in his thigh and will need to be managed over the next couple of weeks," said WRU national medical performance manager Prav Mathema.
"Although the injury is mild, Spala will be an intense training camp and Morgan will not get the maximum benefit out of it with the injury he is carrying.
"We have consulted closely with the Scarlets medical team and concluded the best thing for him is to miss this first trip and get himself right in time for the second one."
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The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
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