B737-800
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Time Pressure
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Flight Crew FLC Overrode Automation
Human Factors; Procedure
Flying the DRLLR 5 Arrival to IAH. Told to expect the RNAV Y 26R. Briefed a vector to intercept but were given RNAV Y beginning at SKLER. Engaged heading select to follow approach as I was changing the FMC to use the SKLER transition. ATC gave us a heading and cleared us for a visual approach Runway 26R. Approach and landing uneventful from that point on. We expected a vector for an intercept to the RNAV Y RWY 26R. When assigned the RNAV Y 26R from SKLER we were over SKLER and rushed in an attempt to comply with the unexpected clearance. ATC appeared to expect what we did and issued a visual approach from our present position. I do not recall receiving an earlier expect approach clearance beginning at SKLER. That would have had us brief and execute the approach as expected by ATC. We had never flown this arrival/approach procedure to RWY 26R but in retrospect we should have briefed all approach options more thoroughly.
B737-800 Captain reported a track deviation occurred following a late clearance to fly the IAH RNAV Y 26R approach.