After a stunning start to the season, Valencia have suffered five defeats in a row and Los Che will need to produce something special to turn their Copa del Rey tie around.
Last week's first leg at the Camp Nou saw Barcelona record a 1-0 win, meaning a clean sheet at Mestalla would see the Blaugrana into the final once more.
Lionel Messi was rested for the weekend visit to Espanyol and will come back into the starting eleven.
At centre-back meanwhile, Barca could give a debut to Colombian Yerry Mina with Thomas Vermaelen out injured.
The first leg saw Valencia visit the Camp Nou without Ezequiel Garay, Geoffrey Kondogbia, Goncalo Guedes and Simone Zaza - all of whom are first choice players.
All but Guedes, however, had recovered to feature in the weekend game at Atletico Madrid and will be pushing for a return on Thursday night.
Hosts to go for it at Mestalla
Valencia know they must score to have any chance of progressing and they will be a lot more attacking than in the first leg.
At the Camp Nou, Los Che barely threatened but at home with nearly a full strength team and needing to score at least once, we should expect the hosts to show much more attacking intent.
That in turn should lead to a more open game, although Valencia will retain some caution knowing that if Barca score, Los Che will need to net three times.
Tips and predictions
Both team to score and over 2.5 goals is priced at 8/11 (1.73), which is a solid way to back an open game and has paid out in five of Valencia's last seven home games.
Risk Free 20: New customers only, limited to one per person. If you’ve previously had a Paddy Power account, you will not qualify for the offer. Place your FIRST bet on any Sportsbook market and if it loses we will refund your stake in CASH. Max refund for this offer is €20. Only deposits made using Cards or Paypal will qualify for this promotion. T&Cs apply.Over 2.5 goals and both teams to score at 8/11 (1.73) for a 2pt stake with Paddy Power