The 22-year-old has made 18 appearances for the Capital side in his career and recently signed a contract extension which ties him to BT Murrayfield until the summer of 2021, but Edinburgh feel that his development will be aided by linking up with the Allianz Park outfit for the 2019/20 campaign.
Edinburgh head coach Richard Cockerill said: “With several locks returning to fitness, coupled with our recent second-row recruitment, an opportunity has arisen for Callum to continue his rugby development at Allianz Park. Callum is a prospect for the future and this move benefits both us and the player.”
Edinburgh completed the signing of Sam Thomson on Thursday, swelling their options at lock. They enter the new season with Thomson, Lewis Carmichael, Murray Douglas, Jamie Hodgson and Fraser McKenzie as options in the second row, while their ranks will be reinforced after the World Cup when Ben Toolis and Grant Gilchrist return from Scotland duty.
Edinburgh, meanwhile, are in action on Saturday afternoon when they face the Ospreys at BT Murrayfield (kick-off 3pm). It is their final warm-up match before they begin their Guinness PRO14 season against Italian side Zebre on Saturday, September 28.