Practice "drop it" and "leave it"
Spent 15 mins playing fetch with Sadie in the backyard. Put her in a sit, threw the tennis ball, gave her the fetch command. She executed well. Brought the ball back to me and dropped it on command. Didn't use the second tennis ball, so she has made real progress over the week.
Repeated a few rounds of drop it and leave it. She did well and only went for the ball when I gave her the release.
"Drop it" and "leave it" with long fetches in the field this evening giving Sadie a few more distractions.