Athletic Bilbao's Spanish goalkeeper Unai Simon grabs the ball during the Spanish league football match Real Madrid CF against Athletic Club Bilbao at the Santiago Bernabeu stadium in Madrid on Dec 22, 2019. (JAVIER SORIANO / AFP)

MADRID - The quarterfinalists of Spain's Copa del Rey will be decided this week as the knockout competition draws on apace.

The first of this week's eight matches is played in Tenerife, where the second division hosts entertain Athletic Bilbao.

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Tenerife go into the game after defeating Valladolid last week, but with one eye on their delicate position just above the relegation zone in the Segunda Liga. They are also without left-back and former Athletic youth teamer Ismael Lopez, after the 29 year-old underwent an appendix operation.

Athletic fly to the Canary Islands after a 1-1 draw away to Espanyol that they could have won but for a failure to turn chances into goals

Athletic fly to the Canary Islands after a 1-1 draw away to Espanyol that they could have won but for a failure to turn chances into goals.

Last week saw them struggle into the last 16 after a nail-biting game away to fellow second division outfit Elche, and after the game ended 1-1 after extra-time, they looked to be on the verge of crashing out after falling 3-1 behind in the penalty shootout before a miraculous recovery.

Athletic coach Gaizka Garitano has first-choice keeper Unai Simon available again after a two-week absense with mumps, but is likely to continue with Iago Herrerin in goal.

Meanwhile, Mikel Balenziaga is likely to return at left-back for Athletic, with Unai Nunez continuing in central defense, while Unai Lopez could come back into central midfield.

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Raul Garcia should start after only playing 20 minutes at the weekend, while young forward Asier Villalibre is finally finding his feet in the first-team after netting his first league goal against Espanyol.

Wednesday sees the bulk of the other Copa del Rey games, with Real Madrid visiting Zaragoza, who famously beat them 6-1 in the La Romareda Stadium in 2006, while Leganes visit the Camp Nou on Thursday when their defensive organization will once again test Quique Setien's FC Barcelona.