https://help.yahoo.com/kb/fantasy-hockey/SLN7058.html
Please note: If the position change is considered temporary or situational, position eligibility will NOT be adjusted. For example, a left-winger who plays at center for a game or two to account for an injury, then returns to left-winger (LW), will NOT receive center (C) eligibility.
Players will not lose position eligibility when moving from one position to another. If a right-winger (RW) moves to LW during the season, he will be eligible for the remainder of the season at both RW and LW.

