diff --git a/changelog.d/7421.misc b/changelog.d/7421.misc
new file mode 100644
index 000000000..676f28537
--- /dev/null
+++ b/changelog.d/7421.misc
@@ -0,0 +1 @@
+Move catchup of replication streams logic to worker.
diff --git a/synapse/replication/tcp/handler.py b/synapse/replication/tcp/handler.py
index 2d1d119c7..bf4f1a594 100644
--- a/synapse/replication/tcp/handler.py
+++ b/synapse/replication/tcp/handler.py
@@ -262,7 +262,7 @@ class ReplicationCommandHandler:
                 # `POSITION` command yet, and so we may have missed some rows.
                 # Let's drop the row for now, on the assumption we'll receive a
                 # `POSITION` soon and we'll catch up correctly then.
-                logger.warning(
+                logger.debug(
                     "Discarding RDATA for unconnected stream %s -> %s",
                     stream_name,
                     cmd.token,