Raptors 905 are out the only head coach they’ve ever known.

Jesse Mermuys will leave his post behind the 905 bench to join Luke Walton’s staff with the Los Angeles Lakers. The news was first reported by Dave Miller and confirmed by Chris Reichert of Upside & Motor. (Raptors Republic has been aware of the move for some time, but with Walton still coaching in the NBA Finals, no contracts have been signed.)

Mermuys and Walton have a long-standing relationship, and losing Mermuys is something that was believed to be a possibility once Walton accepted the Lakers’ head coaching gig. The 35-year-old Mermuys joined the Toronto Raptors as an assistant for the 2013-14 season after spending four seasons as a video coordinator, advanced scout, and assistant for the Denver Nuggets and one with the Houston Rockets as an assistant and director of player development. Prior to his NBA coaching career, Mermuys spent time at Arizona under Lute Olson (also a Walton mentor) as the program’s director of basketball operations.

After two seasons on the Raptors’ bench, he was named the first ever head coach of Raptors 905, the Raptors’ shiny new D-League affiliate. Mermuys, who also acted as the team’s assistant general manager, helped lead the 905 to a 23-27 record in their expansion season, including an impressive 18-9 run to close the season despite multiple injuries and call-ups.

The entire inaugural season was a resounding success for the D-League program, with that late-season entropy highlighting the myriad ways in which Mermuys and company proved effective. Norman Powell, Greg Smith, Axel Toupane, and a host of others were all put in positions to improve, succeed, and advance, and even through the heavy turnover and with the dearth of experience, the 905 managed the No. 6 defense in the league and a very strong finish.

That success is a credit to the entire organization, to be sure, but the loss of Mermuys is a big one. Not only has Mermuys proven to be a strong player development coach, he improved as a tactician as the season went on, and he’s exactly the type of employee the culture-driven Raptors hold in high regard, a hard-working, unrelentingly positive, quality person. That’s going to be missed around the Hershey Centre, but sometimes the cost of employing good people is that, well, they’re good people, and they’re going to get bigger and better opportunities as a result (and the Raptors gave permission for the Lakers to speak to him, as most organizations would).

In Mermuys, the Lakers get a strong talent development voice and an upbeat presence to help bring along their young core.

It’s unclear who the Raptors may look to as a replacement for Mermuys as the coach of the 905. David Gale, Tim Lewis, and Nathaniel Mitchell were Mermuys’ assistants but the name to watch is Jama Mahlalela, who will coach the Las Vegas Summer League team, a former Mermuys duty.

The Swaziland-born Raptors assistant and former UBC Thunderbird has been one of Dwane Casey’s assistant coaches since 2013-14 and has earned rave reviews for his work with the team’s young players, to the point that he’s generally the one running the team’s pre-draft prospect workouts. Losing him from the NBA bench would be a tough subtraction, but if the organization wants to maintain that same positive voice and keep a proven developer at the helm, Mahlalela makes all the sense in the world. There’s really not a more energetic, positive person out there.

Prior to joining the Raptors’ staff, Mahlalela spent two years as the team’s director of player development. He previously worked with NBA Cares and was (and remains) heavily involved with youth basketball organizations.

If not Mahlalela – the team hasn’t confirmed a successor yet – Gale is probably the next most likely in-house candidate. A Loyola-Chicago product, Gale spent four years with the Clippers in a video coordinator role before joining the Raptors in a similar capacity in 2011, then being named to the 905 staff for last season. He’s also coordinated L.A.-based workouts for some of the team’s players over the last few summers.

In any case, Year Two for the 905 will be a little different.

READ MORE ON MERMUYS’ DEPARTURE HERE.