Everton’s full-back gamble is set to be tested once again in the Merseyside derby.

The Blues are sweating on the availability of Vitalii Mykolenko after the left back was withdrawn from the squad that faced Bournemouth after flagging a calf concern on Saturday morning.

Whether the left back will be fit to return for Wednesday night is one of the defining issues of the Blues’ preparations for the game. It has added importance given David Moyes does not expect to have either of his specialist right backs available, placing a heavy responsibility on 39-year-old Ashley Young.

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Everton have now assessed the full-back situation under two different managers this season, reaching the same conclusion on both occasions. The Blues were busy in the summer transfer window but, still having to be savvy over how deals were constructed, had to make tough decisions on where to strengthen and how.

Regulatory concerns led to the sale of Ben Godfrey - who played much of the second half of last season at right back - as part of efforts to avoid another breach of the Premier League’s Profit and Sustainability Regulations (PSR).

The same issue was a drag on spending and, as director of football Kevin Thelwell assessed where to commit what money was available on loan deals and buy-now, pay-later moves, the decision was taken to focus on the area of greatest need. Everton’s defence was a cornerstone of the form that would have seen the club finish mid-table last season without being hit by two points deductions. Goals were the big problem.

Unable to strengthen in every area, the belief was Everton could afford to enter the season with the players they had. Without Godfrey, that meant banking on the availability of club captain Seamus Coleman, Nathan Patterson and Vitalii Mykolenko, with Ashley Young acting as cover on both sides and central midfielder James Garner seen as a viable back-up on the right - where he had played as England Under-21s won the Euros the previous summer.

The gamble immediately came under pressure. Coleman had started pre-season looking strong but Patterson was set to be unavailable for the opening weeks as he completed his recovery from the hamstring injury suffered at Chelsea in April. Mykolenko started the campaign after an injury-laden summer in which his problems had begun when he was withdrawn midway through the derby win at Goodison.

When Young was brought in to cover for an injured Coleman he was shown a red card in the opening day defeat to Brighton and Hove Albion - a game Garner also missed through. One week later, Dyche turned to teenager Roman Dixon, lifting him from the academy for a senior debut away at Tottenham Hotspur.

Eventually, the problems eased but Coleman and Patterson’s injury issues continued and it took Young’s redemption at right back to help Everton through the autumn and winter months, when results proved tough to come by but the defensive record improved as attacking intent was sacrificed.

Full-back was an area that came under focus again in January, but for a second consecutive window, it was not deemed a priority. With PSR still limiting what Everton could spend, domestic loan spots already used up and Moyes inheriting a relegation-threatened side that had taken 81 minutes to register a shot on target against Nottingham Forest at the end of December and then failing to test the goalkeeper once at Bournemouth, Dyche’s final game, the emphasis was placed on creativity.

Heading into the final days of the window it was the completion of the deal for attacking midfielder Carlos Alcaraz and the search for a striker that took up attention as Dominic Calvert-Lewin, Armando Broja and Youssef Chermiti suffered serious injuries across a brutal month in which Dwight McNeil’s knee problem persisted and Orel Mangala was hit by season-ending anterior cruciate ligament damage.

Those problems meant that, while it was again accepted full-back was an area where support would be helpful, it was felt the squad could still provide cover. That meant that during talks with Chelsea over the potential termination of Broja’s loan, it was midfielder Kiernan Dewsbury-Hall and attack-minded Carney Chukwuemeka who were deemed the most enticing options before Everton decided to retain Broja in the hope he would still be able to play a significant role this year.

While Ben Chilwell did not move to Crystal Palace until deadline day, Everton were looking elsewhere before the Brighton win nine days earlier. The loss of Calvert-Lewin and Mangala to their injuries at the Amex then solidified that decision.

The result is the situation that now threatens to unfold on Wednesday. Patterson is not expected to be available after picking up what is thought to be a minor hamstring problem. It might be too early for Coleman too, who is at the later stage of his recovery from a calf problem. Meanwhile Garner, who has only just returned from the back injury that rendered him absent for months, is in demand in midfield given Mangala’s misfortune.

While Moyes has found a work-around on the right of the defence that has been successful, with Jake O’Brien being utilised on the right across the wins against Tottenham Hotspur, Brighton and Leicester City, the burden on Mykolenko is a heavy one.

The absence of the Ukraine international, should he lose his battle for fitness for the derby, would be an additional blow given his recent displays against Liverpool. Everton have kept consecutive clean sheets at Goodison against Liverpool and Mykolenko has been central to both. He initially fought through injury in the 2-0 win to make it to half-time, and that followed a performance at Anfield in which he helped to keep Mo Salah quiet until the closing stages, when it took a penalty to break the resistance of a Blues side that had been reduced to 10 men at the end of the first half.

Some of Mylolenko’s best displays have been against the Premier League’s most potent right wingers, including Bukayo Saka of Arsenal. At Anfield last season it was also Young who was sent off. Like against Brighton on the opening day, the veteran was at right back when he picked up two bookings - he will likely be on the left, where he is more comfortable, should he be required to start against Liverpool.

But for all his experience, injuries at the back have once again exposed the risk taken across two windows to leave the full back dilemma until the summer to address.