However, both are included in the match day line-up as Head Coach Richard Hill rings the changes and gives his entire squad a chance to stake a claim for more senior rugby before the resumption of league action later this month.
Ben Howard will occupy the opposite wing to Short in the European clash while Jon Clarke plays in the centre with Josh Matavesi.
A new-look half back pairing will see Joe Carlisle combine with scrum half Paul Hodgson, with the former England ace making his first start for Warriors after coming off the bench at Adams Park last weekend.
Ceri Jones, Ollie Hayes and James Currie will join forces in a new front row while Chris Jones moves from the back row to lock to partner Craig Gillies.
Former Ireland international Neil Best and Blair Cowan get their first start of the seasons in the back row alongside Matt Kvesic.
Abbott, who could make his 50th appearance for Warriors in the game, is on the bench alongside Max Stelling who could make his senior debut for the club.
"It's great to see Andy (Short) and Jake (Abbott) back in contention and to also give senior starts this season to the likes of Blair Cowan and Neil Best now they are back fit," said Hill.
"When you play teams you know little about you can't really look to stop them, you have to concentrate on your own performance. It works both ways and they won't know much about us.
"We have had some intelligence from Mark Hewitt (Warriors Academy Manager) from his time in Spain and also a friend of mine in France has been to watch them a number of times and reported back so it is not a total step into the unknown for us.
"We will give them a huge amount of respect and have picked a strong team with players who have been on the fringes during the first six league games. Now they have an opportunity to stake a claim for a jersey.
"In the first part of the season, with six games back-to-back, it can be hard to break into selection and players have had to be patient while we look for continuity. But with these cup games they have a big chance to put their hand up.
"The team we send to Spain is highly motivated and will perform. Many of these players have seen how we have attacked in the opening weeks of the league season and will be keen to reproduce that. It's an opportunity to express themselves.
"We want to do well in this competition and that starts from day one," added Hill. "We start away in Spain and then play Rovigo at home, we need to win those games and set ourselves up for the Perpignan double header.
"We have to start on the front foot and we won't be taking Bizkaia Gernika lightly. Our team is hungry to play and desperate to get a good performance and get through the group stages of this exciting competition.
Warriors vs. Bizkaia Gernika RT
15 Chris Pennell
14 Ben Howard
13 Jon Clarke
12 Josh Matavesi
11 Andy Short
10 Joe Carlisle
9 Paul Hodgson
1 Ceri Jones
2 Ollie Hayes
3 James Currie
4 Chris Jones
5 Craig Gillies
6 Neil Best (c)
7 Matt Kvesic
8 Blair Cowan
16 Ed Shervington
17 George Porter
18 Rob O'Donnell
19 Dean Schofield
20 Jake Abbott
21 Ollie Frost
22 Max Stelling
23 Alex Grove