No, they were already bringing up Rodriguez and were going to send down another pitcher, probably Winder. The Rodriguez move had been announced and Larnach was listed in the starting lineup, but with Thielbar surprisingly going on the Il, they were able to call up Kirilloff, who otherwise would be frozen in AAA until 5/10.
The rosters are capped at 13 pitchers, so they couldn’t add another pitcher without subtracting one.