diff --git a/Configuration/PyReleaseValidation/README.md b/Configuration/PyReleaseValidation/README.md
index d56aada97ef1f..1a0d1913ad2c5 100644
--- a/Configuration/PyReleaseValidation/README.md
+++ b/Configuration/PyReleaseValidation/README.md
@@ -65,8 +65,8 @@ The offsets currently in use are:
 * 0.7561 HLT phase-2 timing menu Alpaka, trimmed tracking
 * 0.7562 HLT phase-2 timing menu Alpaka, trimmed tracking, single tracking iteration variant
 * 0.757: HLT phase-2 timing menu Alpaka, single tracking iteration, LST seeding + CKF building variant
-* 0.7571: HLT phase-2 timing menu Alpaka, single tracking iteration, LST seeding + mkFit building variant
-* 0.7572: HLT phase-2 timing menu Alpaka, single tracking iteration, LST seeding + mkFit building and fitting variant
+* 0.7571: HLT phase-2 timing menu Alpaka, single tracking iteration, Phase2CAExtension+LST seeding + mkFit building variant
+* 0.7572: HLT phase-2 timing menu Alpaka, single tracking iteration, Phase2CAExtension+LST seeding + mkFit building and fitting variant
 * 0.758 HLT phase-2 timing menu ticl_barrel variant
 * 0.759: HLT phase-2 timing menu, with NANO:@Phase2HLT
 * 0.76: HLT phase-2 reduced menu, with DIGI step
diff --git a/Configuration/PyReleaseValidation/python/relval_Run4.py b/Configuration/PyReleaseValidation/python/relval_Run4.py
index 7779af70db772..8dc6fafa9eb67 100644
--- a/Configuration/PyReleaseValidation/python/relval_Run4.py
+++ b/Configuration/PyReleaseValidation/python/relval_Run4.py
@@ -81,8 +81,8 @@
 numWFIB.extend([prefixDet+34.7561])# HLTTiming75e33, alpaka,phase2_hlt_vertexTrimming
 numWFIB.extend([prefixDet+34.7562])# HLTTiming75e33, alpaka,phase2_hlt_vertexTrimming,singleIterPatatrack
 numWFIB.extend([prefixDet+34.757]) # HLTTiming75e33, alpaka,singleIterPatatrack,trackingLST,seedingLST
-numWFIB.extend([prefixDet+34.7571]) # HLTTiming75e33, alpaka,singleIterPatatrack,trackingLST,seedingLST,buildingMkFit
-numWFIB.extend([prefixDet+34.7572]) # HLTTiming75e33, alpaka,singleIterPatatrack,trackingLST,seedingLST,buildingMkFit,fittingMkFit
+numWFIB.extend([prefixDet+34.7571]) # HLTTiming75e33, alpaka,singleIterPatatrack,Phase2CAExtension,trackingLST,seedingLST,buildingMkFit
+numWFIB.extend([prefixDet+34.7572]) # HLTTiming75e33, alpaka,singleIterPatatrack,Phase2CAExtension,trackingLST,seedingLST,buildingMkFit,fittingMkFit
 numWFIB.extend([prefixDet+34.758]) # HLTTiming75e33, ticl_barrel
 numWFIB.extend([prefixDet+34.759]) # HLTTiming75e33 + NANO
 numWFIB.extend([prefixDet+34.77])  # NGTScouting
diff --git a/Configuration/PyReleaseValidation/python/upgradeWorkflowComponents.py b/Configuration/PyReleaseValidation/python/upgradeWorkflowComponents.py
index f7676b5f71343..97e781a51ea3c 100644
--- a/Configuration/PyReleaseValidation/python/upgradeWorkflowComponents.py
+++ b/Configuration/PyReleaseValidation/python/upgradeWorkflowComponents.py
@@ -2032,7 +2032,7 @@ def condition(self, fragment, stepList, key, hasHarvest):
 upgradeWFs['HLTTiming75e33AlpakaSingleIterLSTSeedingMkFitBuilding'].offset = 0.7571
 upgradeWFs['HLTTiming75e33AlpakaSingleIterLSTSeedingMkFitBuilding'].step2 = {
     '-s':'DIGI:pdigi_valid,L1TrackTrigger,L1,L1P2GT,DIGI2RAW,HLT:75e33_timing,VALIDATION:@hltValidation',
-    '--procModifiers': 'alpaka,singleIterPatatrack,trackingLST,seedingLST,trackingMkFitCommon,hltTrackingMkFitInitialStep',
+    '--procModifiers': 'alpaka,phase2CAExtension,singleIterPatatrack,trackingLST,seedingLST,trackingMkFitCommon,hltTrackingMkFitInitialStep',
     '--datatier':'GEN-SIM-DIGI-RAW,DQMIO',
     '--eventcontent':'FEVTDEBUGHLT,DQMIO'
 }
@@ -2045,7 +2045,7 @@ def condition(self, fragment, stepList, key, hasHarvest):
 upgradeWFs['HLTTiming75e33AlpakaSingleIterLSTSeedingMkFitBuildingFitting'].offset = 0.7572
 upgradeWFs['HLTTiming75e33AlpakaSingleIterLSTSeedingMkFitBuildingFitting'].step2 = {
     '-s':'DIGI:pdigi_valid,L1TrackTrigger,L1,L1P2GT,DIGI2RAW,HLT:75e33_timing,VALIDATION:@hltValidation',
-    '--procModifiers': 'alpaka,singleIterPatatrack,trackingLST,seedingLST,trackingMkFitCommon,hltTrackingMkFitInitialStep,trackingMkFitFit',
+    '--procModifiers': 'alpaka,phase2CAExtension,singleIterPatatrack,trackingLST,seedingLST,trackingMkFitCommon,hltTrackingMkFitInitialStep,trackingMkFitFit',
     '--datatier':'GEN-SIM-DIGI-RAW,DQMIO',
     '--eventcontent':'FEVTDEBUGHLT,DQMIO'
 }
diff --git a/Configuration/PyReleaseValidation/scripts/runTheMatrix.py b/Configuration/PyReleaseValidation/scripts/runTheMatrix.py
index 9eeb4612b214a..b21de405e5c1c 100755
--- a/Configuration/PyReleaseValidation/scripts/runTheMatrix.py
+++ b/Configuration/PyReleaseValidation/scripts/runTheMatrix.py
@@ -167,8 +167,8 @@ def runSelected(opt):
                      29634.7561,  # HLT phase-2 timing menu Alpaka, trimmed tracking
                      29634.7562,  # HLT phase-2 timing menu Alpaka, trimmed tracking, single tracking iteration variant
                      29634.757,   # HLT phase-2 timing menu Alpaka, single tracking iteration, LST seeding + CKF building variant
-                     29634.7571,  # HLT phase-2 timing menu Alpaka, single tracking iteration, LST seeding + mkFit building variant 
-                     29634.7572,  # HLT phase-2 timing menu Alpaka, single tracking iteration, LST seeding + mkFit building and fitting variant
+                     29634.7571,  # HLT phase-2 timing menu Alpaka, single tracking iteration, Phase2CAExtension+LST seeding + mkFit building variant
+                     29634.7572,  # HLT phase-2 timing menu Alpaka, single tracking iteration, Phase2CAExtension+LST seeding + mkFit building and fitting variant
                      29634.758,   # HLT phase-2 timing menu ticl_barrel variant
                      29634.759,   # HLT phase-2 timing menu, with NANO:@Phase2HLT
                      29634.77,    # HLT phase-2 NGT Scouting menu
diff --git a/HLTrigger/Configuration/python/HLT_75e33/eventsetup/hltESPMkFit_cfi.py b/HLTrigger/Configuration/python/HLT_75e33/eventsetup/hltESPMkFit_cfi.py
index 9249c5ee1b778..4cb85738cb79a 100644
--- a/HLTrigger/Configuration/python/HLT_75e33/eventsetup/hltESPMkFit_cfi.py
+++ b/HLTrigger/Configuration/python/HLT_75e33/eventsetup/hltESPMkFit_cfi.py
@@ -17,5 +17,16 @@ def _addProcesshltInitialStepMkFitConfig(process):
         minPt = cms.double(0.8)
     )
 
+def _addProcesshltLSTStepMkFitConfig(process):
+    process.hltInitialStepTrackCandidatesMkFitConfig = cms.ESProducer("MkFitIterationConfigESProducer",
+        ComponentName = cms.string('hltInitialStepTrackCandidatesMkFitConfig'),
+        appendToDataLabel = cms.string(''),
+        config = cms.FileInPath('RecoTracker/MkFit/data/mkfit-phase2-lstStep.json'),
+        maxClusterSize = cms.uint32(8),
+        minPt = cms.double(0.9)
+    )
+
 from Configuration.ProcessModifiers.hltTrackingMkFitInitialStep_cff import hltTrackingMkFitInitialStep
-modifyConfigurationForTrackingMkFithltInitialStepMkFitConfig_ = hltTrackingMkFitInitialStep.makeProcessModifier(_addProcesshltInitialStepMkFitConfig)
+from Configuration.ProcessModifiers.seedingLST_cff import seedingLST
+modifyConfigurationForTrackingMkFithltInitialStepMkFitConfig_ = (~seedingLST & hltTrackingMkFitInitialStep).makeProcessModifier(_addProcesshltInitialStepMkFitConfig)
+modifyConfigurationForTrackingMkFithltLSTStepMkFitConfig_ = (seedingLST & hltTrackingMkFitInitialStep).makeProcessModifier(_addProcesshltLSTStepMkFitConfig)
diff --git a/HLTrigger/Configuration/python/HLT_75e33/modules/hltInitialStepTrackCandidates_cfi.py b/HLTrigger/Configuration/python/HLT_75e33/modules/hltInitialStepTrackCandidates_cfi.py
index f1f58c4aee220..a1a69270fccf6 100644
--- a/HLTrigger/Configuration/python/HLT_75e33/modules/hltInitialStepTrackCandidates_cfi.py
+++ b/HLTrigger/Configuration/python/HLT_75e33/modules/hltInitialStepTrackCandidates_cfi.py
@@ -72,8 +72,12 @@
     ttrhBuilder = cms.ESInputTag("","WithTrackAngle")
 )
 
-_hltInitialStepTrackCandidatesMkFitLSTSeeds = _hltInitialStepTrackCandidatesMkFit.clone(seeds = "hltInitialStepTrajectorySeedsLST")
-                                                     
+_hltInitialStepTrackCandidatesMkFitLSTSeeds = _hltInitialStepTrackCandidatesMkFit.clone(
+    seeds = "hltInitialStepTrajectorySeedsLST",
+    candMinNHitsCut = 4,
+    candMinPtCut = 0.9
+)
+
 from Configuration.ProcessModifiers.singleIterPatatrack_cff import singleIterPatatrack
 from Configuration.ProcessModifiers.trackingLST_cff import trackingLST
 from Configuration.ProcessModifiers.seedingLST_cff import seedingLST