What goalie in recent memory was a good starter elsewhere soon before or soon after failing here?
Just for the fun of it. After they left the crease in Toronto:
Garret Sparks:
In his first year since leaving Toronto, he's a .904 SV% platoon/backup goalie in the AHL.
Curtis McElhinney:
He's remained a backup goalie since leaving Toronto. His numbers are down since leaving the Leafs, but he's still posted a respectable .911 SV% in two seasons as a back-up for Carolina last year & Tampa this year.
James Reimer:
Probably the most successful of our ex-goalies. While he's never been a clear-cut starter in the four years since leaving Toronto, he's been the 1A or 1B goalie in a platoon every season, and is sporting a .913 SV% over that span.
Jonathan Bernier:
Bernier has fared slightly worse, but pretty similar to James Reimer in his post-Leaf career. He's averaging about 35 games per year as a platoon/backup goalie, with a .910 SV% over that span.
Ben Scrivens:
Had a pretty good year as a platoon/backup in a season split between LA and Edmonton his first year after leaving Toronto. He then had a horriawful year as a starter in Edmonton where he posted an .890 SV% in 57 games. He then bounced between the AHL and Montreal for a year, had two OK'ish years as a starter in the KHL and appears to have retired from pro hockey after the 2017-18 season.
Jonas "THE MONSTER" Gustavsson:
Kicked around in the NHL for five more years after leaving Toronto as a mediocre backup for Detroit, Boston & Edmonton, with a few stints in the AHL along the way, before leaving for Sweden in 2017-18, where he's still playing to this day as an OK starter in that league.
Jean-Sebastien Giguere:
Played three more seasons in the NHL after leaving Toronto as an OK backup in Colorado before calling it a career.
Vesa Toskala
Traded by the Leafs to Anaheim, who immediately banished him to the press box. He was subsequently traded to Calgary where he finished up as their backup goalie. The following season he sat out almost the entire season, eventually playing two games in the Swedish Elite League (posting an .898 SV%).
He went to the Finnish league the following year, and after posting a 1-15-5 record & .885 SV% through 22 games, he reportedly got drunk, lit his goalie equipment on fire and left the team. About a year later, he formally announced his retirement.
Andrew Raycroft
Spent four more years in the NHL as a mediocre backup goalie for three different teams, before eventually getting banished to the AHL (where he put up an .891 SV% in 21 games). He then spent one year as an OK starter in the Italian Hockey League, followed by one year as an .896 SV% starting goalie in the Swedish Elite League before calling it a career.
Jean-Sebastien Aubin:
Played one more year in the NHL as a .886 SV% backup goalie for LA, before ending up in the AHL and then Europe to finish up his career.
Ed Belfour:
Played one more season in the NHL with Florida, where he put up a .902 SV% in 58 games for Florida, followed by one season in Sweden, before he retired to a life of non-stop partying and excessive drinking.
Curtis Joseph
Lasted all of one-and-a-half seasons as Detroit's starter, posting a .911 SV% in that span, before the Red Wings quickly realized he wasn't the elite MVP calibre goalie he'd been advertised to be by the Toronto media and they brought Dominik Hasek out of retirement to replace him.
After Detroit, he was an abysmal starter for Phoenix for two seasons, a sub-par backup for two more years after that for Calgary & Toronto, and then he retired.
Felix Potvin:
Quickly became a journeyman after leaving Toronto, bouncing between five different organizations where he rarely did better than a .905 SV% as either a starter or a backup goalie.
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Honestly...I could probably keep going, but I'll stop here.