UPDATE 03.07, 10:33am CET:
Reports from Spain suggest that Bale is feeling just fine and should be ready to start tonight.
Real Madrid attacker Gareth Bale did not complete Monday's training session with the rest of the squad and is questionable for Tuesday's Champions League match against Napoli, according to Spanish TV TVE.
Gareth Bale did not complete today's training with the squad and he is questionable for Tuesday's match, according to TVE. Wow.— Lucas Navarrete (@LucasNavarreteM) March 6, 2017
TVE's report did not explain what kind of problem Bale has, although EsRadio's journalist Sergio Valentin tweeted later that Bale "doesn't have an injury and nothing serious is going on."
The Welshman recently recovered from an ankle injury which kept him out of the team three months and missed Saturday's match against Eibar after the red card he saw on the 3-3 draw to Las Palmas.
Bale has been consistently out of the team every season because of his injuries and it seems that he is very injury-prone. If he is not ready to go against Napoli, expect Lucas Vazquez to start on Real's right wing with Cristiano Ronaldo and Karim Benzema upfront.
Real hold a 3-1 lead on aggregate.