The Italians meanwhile are offered at 8/5 (2.60) to qualify and 5/2 (3.50) to win on the night, while Athletic are offered at 11/10 (2.10) to record a win in the first ever game at the fully completed new San Mames stadium.
Indeed Athletic's new ground is a fitting stage for a game of this magnitude and it is a 53,000 sell out for the biggest game in the last 16 years for the side from Bilbao.
In last week's first leg Ernesto Valdverde's men were excellent for large spells and manage to keep a dangerous Napoli side quiet for large spells.
With the away goal, the Basques know a 0-0 draw would be enough to send them through, but Athletic do not really do goalless draws.
It has been 35 matches and nearly two years since one of their home encounters ended in a stalemate without goals and that run is unlikely to come to an end this evening.
Last season Athletic Bilbao's home games in all competitions tended to be high scoring affairs with 14 of their games seeing over 2.5 goals scored.
A repeat is offered 23/25 (1.92) and could well be worthy of consideration. However for some bigger odds the price of 57/50 (2.14) for over 1.5 goals in the second half looks appealing.
This bet paid out 15 times last season during Athletic's home games, with the side often starting a little slow at home only to come good in the second half.
With so much on the line there is every chance that the second 45 minutes will see either one or both sides really going for it, which in turn should mean goals.
|Over 1.5 goals second half at 57/50 (2.14) for a 1.5pt stake with Unibet|
Sign up with Unibet for a free bet of up to £20 and back Phil's selection for this match
Phil Kitromilides is a sports journalist and TV presenter in Madrid