Monday's 3-0 loss at Crystal Palace leaves the Gunners in sixth place, but results at the weekend saw Wenger's side drop to seventh - 10 points off the top four.
Arsenal are in serious risk of failing to qualify for next season's Champions League for the first time under Wenger, with the pressure on the manager reaching new heights in recent weeks.
Finishing below north London rivals Tottenham, also for the first time under Wenger, is an almost certainty but will be confident of beating a Boro side without a win in 14 top-flight games.
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Middlesbrough host Arsenal at the Riverside with kick-off scheduled for 8pm on Monday, April 17.
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Gaston Ramirez is set to return for Middlesbrough having missed the last two games with an ankle injury and is expected to go straight back into interim boss Steve Agnew's starting line-up.
Boro are still without Fabio and George Friend while Calum Chambers also misses out against his parent club.
Provisional squad: Valdes, Guzan, Barragan, Gibson, Espinosa, Ayala, Husband, Fry, De Roon, Clayton, Forshaw, Leadbitter, Guedioura, Downing, Stuani, Traore, Fischer, Ramirez, Negredo, Gestede, Bamford.
Arsenal could welcome back captain Laurent Koscielny and first-choice goalkeeper Petr Cech.
Koscielny has sat out the last two games after injuring his Achilles against Manchester City while Cech has been sidelined with a calf problem.
Arsene Wenger rates their chances of being involved at the Riverside as 80 per cent, but Lucas Perez (thigh) and David Ospina (back) remain absent.
Provisional squad: Cech, Martinez, Macey, Bellerin, Holding, Gabriel, Koscielny, Mertesacker, Mustafi, Monreal, Gibbs, Maitland-Niles, Coquelin, Xhaka, Ramsey, Oxlade-Chamberlain, Ozil, Walcott, Reine-Adelaide, Iwobi, Sanchez, Giroud, Welbeck.
Middlesbrough starting XI: Valdes; Ayala; Bernardo, Gibson; Barragan, Clayton, Leadbitter, Ramirez, Downing; Stuani, Gestede
Arsenal starting XI: Cecg; Bellerin, Mustafi, Koscielny, Monreal; Xhaka, Elneny; Walcott, Ozil, Sanchez; Welbeck
BETTING ODDS (via 888 Sport)
- Middlesbrough to win: 11/2
- Arsenal to win: 18/5
- Draw: 1/2
Click here to place a bet. Odds correct as of April 17 at 5pm.