b-r.com has a "leverage index" that looks at the game situation when a pitcher enters the game, saying nothing about his results once on the mound. On the Twins, for example, Rogers (1.47), Gomez (1.46), Morris (1.36) and Banda (1.35) lead the staff in highest leverage, which sort of confirms the eye test as to when they get brought in, and also perhaps attests to Shelton's strategy to spread the opportunities around instead of having a rigid setup-closer pecking order. By contrast, Laweryson has a very low 0;70 leverage index, again conforming to what you might expect for a pitcher of his current caliber.
On the Jays this year, it's hardly surprising that Louis Varland's usage results in a very high 1.90 leverage index. Tommy Nance? 0.53.
John Schneider apparently has had very low confidence in Nance. Take it for what it's worth.
Maybe Shelton/Hawkins/Maki will work some magic with him and get good performance, when the game is on the line, that Schneider didn't feel was possible.