The current row started over extendedplayer release from the Welsh regions for Wales coach Gatland who wanted extra time to prepare his Six Nations champions for their Cardiff clash with world champions South Africa on 8 November.
Brendan Shanahan, the NHL's senior vice president of hockey operations and player safety, said Volchenkov extended his elbow on the play rather than making a full body check.
Collymore, who played the last of his 30 Tests in 2007 and joined Sussex the following year as a Kolpak player, has taken the decision to leave the new Division Two champions to be closer to his extended family who live in London.