diff --git a/tsdb/head_append.go b/tsdb/head_append.go
index 539884e74b..2cfd0785ee 100644
--- a/tsdb/head_append.go
+++ b/tsdb/head_append.go
@@ -451,23 +451,7 @@ func (a *headAppender) Append(ref storage.SeriesRef, lset labels.Labels, t int64
 		// we do not need to check for the difference between "unknown
 		// series" and "known series with stNone".
 	}
-
-	s.Lock()
-	defer s.Unlock()
-	// TODO(codesome): If we definitely know at this point that the sample is ooo, then optimise
-	// to skip that sample from the WAL and write only in the WBL.
-	isOOO, delta, err := s.appendable(t, v, a.headMaxt, a.minValidTime, a.oooTimeWindow)
-	if err == nil {
-		if isOOO && a.hints != nil && a.hints.DiscardOutOfOrder {
-			a.head.metrics.outOfOrderSamples.WithLabelValues(sampleMetricTypeFloat).Inc()
-			return 0, storage.ErrOutOfOrderSample
-		}
-		s.pendingCommit = true
-	}
-	if delta > 0 {
-		a.head.metrics.oooHistogram.Observe(float64(delta) / 1000)
-	}
-	if err != nil {
+	if err := a.appendFloat(s, t, v, a.hints != nil && a.hints.DiscardOutOfOrder); err != nil {
 		switch {
 		case errors.Is(err, storage.ErrOutOfOrderSample):
 			a.head.metrics.outOfOrderSamples.WithLabelValues(sampleMetricTypeFloat).Inc()
@@ -483,14 +467,6 @@ func (a *headAppender) Append(ref storage.SeriesRef, lset labels.Labels, t int64
 	if t > a.maxt {
 		a.maxt = t
 	}
-
-	b := a.getCurrentBatch(stFloat, s.ref)
-	b.floats = append(b.floats, record.RefSample{
-		Ref: s.ref,
-		T:   t,
-		V:   v,
-	})
-	b.floatSeries = append(b.floatSeries, s)
 	return storage.SeriesRef(s.ref), nil
 }
 
diff --git a/tsdb/head_append_v2.go b/tsdb/head_append_v2.go
index 0af4b2bdd3..9648d8079e 100644
--- a/tsdb/head_append_v2.go
+++ b/tsdb/head_append_v2.go
@@ -232,16 +232,16 @@ func (a *headAppenderV2) Append(ref storage.SeriesRef, ls labels.Labels, st, t i
 	return storage.SeriesRef(s.ref), partialErr
 }
 
-func (a *headAppenderV2) appendFloat(s *memSeries, t int64, v float64, fastRejectOOO bool) error {
+func (a *headAppenderBase) appendFloat(s *memSeries, t int64, v float64, fastRejectOOO bool) error {
 	s.Lock()
 	// TODO(codesome): If we definitely know at this point that the sample is ooo, then optimise
 	// to skip that sample from the WAL and write only in the WBL.
 	isOOO, delta, err := s.appendable(t, v, a.headMaxt, a.minValidTime, a.oooTimeWindow)
-	if isOOO && fastRejectOOO {
-		s.Unlock()
-		return storage.ErrOutOfOrderSample
-	}
 	if err == nil {
+		if isOOO && fastRejectOOO {
+			s.Unlock()
+			return storage.ErrOutOfOrderSample
+		}
 		s.pendingCommit = true
 	}
 	s.Unlock()