Do you have many slugs? In my neighborhood, they LOVE Delphinium seedlings and like young plants. They leave bugger plants alone. I lost several trays of Delphiniums over two years before I realized that they are NOT vampires, dissolving as soon as the sun hit them on my back porch. The slugs were crawling up the porch stairs and mowing them off at ground level and eating every scrap.
You might pot them up to 3" or 4" pots and keep them somewhere you can protect them from slugs. (Inside under lights?)
If you have enough sprouts, try half the easy way (in the ground, and maybe sprinkle some slug bait).
Try half the safe way (in pots under lights until they are big enough to have a better chance of resisting slugs).