You don't want to lose anyone, but of the three starters Madrigal has by far the least impact in terms of his production vs. his replacement, as compared to by far the worst possible Sox injury (Robert vs. what his ahem "replacements" offer). Eloy's bat is very valuable, and Sox fans were fortunate Mercedes had a great April as well as Vaughn's great play on both sides of the ball, but more surprisingly in the field.
With today's game, with a majority of outs ending in a K, the Sox have been able to regularly play infielders in the outfield (Lamb and Mendick in addition to Vaughan). Can't do that at 2B, but Mendick and Garcia can cover the position well enough defensively. The key to the postseason will be the ability for Robert and Eloy to rehab and return before the AAA season ends. Madrigal's initial timeline gives a good possibility he may return as long as surgery is not required.