Warnock was forced into naming a stop-gap XI for Saturday’s win over Peterborough United with a whole host of defensive casualties missing through injury or suspension.
Full-backs Anfernee Dijksteel and Marc Bola were both unavailable after the latter pulled up late in training, while Darnell Fisher remains a long term absentee.
Lee Peltier was serving a one match ban for an accumulation of yellow cards with centre backs Dael Fry and Grant Hall also out with injuries which look set to keep them sidelined until the November international break.
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It meant Warnock had to shuffle his squad into unfamiliar positions with captain Jonny Howson joining Sol Bamba and Paddy McNair in a defensive three.
Marcus Tavernier and the returning Onel Hernandez were deployed as emergency wing backs with Duncan Watmore in midfield. It was a means to an end, but a one in which Warnock hopes won’t be for the long-term.
But while the makeshift line-up restricted the Posh from registering a single effort on target, with goals from McNair and youngster Josh Coburn sealing an important win at the Riverside on Saturday, Warnock is expecting a more challenging evening with the visit of the Tykes.
“These will give us a bigger test with the players we’ve got missing. The way Barnsley play we’ll have a lot more to do at the back than at the weekend,” he said.
“We’ve got forwards playing as wing-backs, midfielders playing centre-half, Duncan playing midfield. We were all over the show but nobody complained though, so all credit to them and we thoroughly deserved the win.
“There’s a couple of them not training today. We've just got to look after people with three games in such a short space of time.”
Warnock will be boosted by the return of Peltier having completed his suspension with the full-back expected to come straight back into the Boro starting XI.
“You’re always tempted [to keep a winning team]. But when I have done it this year I think we’ve lost anyway so I’ve just got to pick what I think is the best side with the players we’ve got available.
“Sol being the only defender was a bit strange so it’s nice to have Lee available.”
Barnsley arrive in stark contrast to the form they displayed last season when they reached the Championship play-off semi-finals.
Markus Schopp’s side have lost their last four consecutive league games and find themselves in the bottom three but Warnock believes that will stand for nothing when the two sides line-up at the Riverside as Boro go in search of back-to-back wins for the first time this season.
"We’ve not been able to do it yet. We know how difficult it will be,” explained Warnock.
“You’ve just got to look at what they are at the moment and make sure we’re in the right frame of mind.
“They could have won a few more games but they’ll be looking at our record and thinking this is a great game to start our run off.”