Did not start in the 8th stage
126. Maurits Lammertink (nld – Katusha)
Did not start in the 10th stage
176. Daniel Martin (irl – UAE-Emirates)
Withdrawal in the 10th stage
177. Simone Petilli (ita – UAE-Emirates)
Withdrawal in the 11th stage
17. Alexis Gougeard (fra- AG2R)
55. Georg Preidler (aut – Groupama-FDJ)
201. Nacer Bouhanni (fra – Cofidis)
Withdrawal in the 13th stage
123. José Gonçalves (por – Katusha)
Did not start in the 14th stage
148. Dylan van Baarle (nld – Sky)
Withdrawal in the 14th stage
147. Pavel Sivakov (rus – Sky)
Did not start in the 15th stage
65. Bjorg Lambrecht (bel – Lotto-Soudal)
Did not start in the 16th stage
164. Nicola Conci (Ita – Trek Segafredo)
Did not start in the 17th stage
34. Rohan Dennis (aus – BMC)
Withdrawals in the 17th stage
5. Mark Padun (urk – Bahrain Merida)
186. Jordi Simón (spa – Burgos-BH)
Did not start in the 18th stage
7. Hermann Pernsteiner (aut – Bahrain Merida)
153. Simon Geschke (ger – Sunweb)
Did not start in the 19th stage
47. Lukas Pöstlberger (aut – BORA-hansgrohe)
Withdrawal in the 19th stage
93. Laurens De Plus (Bel – Quick-Step Floors)
In last year’s Vuelta a España, 37 riders did not reach Madrid. The most prominent withdrawals were John Degenkolb, Warren Barguil, George Bennett, Sam Oomen, Domenico Pozzovivio, Rohan Dennis, and David de la Cruz.
Vuelta a España 2018: Route map, height profiles, and more
Click on the images to zoom
Stage 4: details Puerto de Alfacar
stage 9: details Alto de la Covatilla
stage 13: details La Camperona
stage 15: details Lagos de Covadonga 
How can I watch this La Vuelta on television? What channel is televising this race?
Depends on where you live. Eurosport is broadcasting La Vuelta in Europe.