Pompey travel to Accrington on Saturday without their midfield general.
Tom Naylor is absent for the trip to the Crown Ground after picking up his fifth league booking of the season against Burton.
The former Derby County midfielder’s tenacious performances have been key during the Blues’ early title charge.
And, to make matters worse, Dion Donohue is sidelined for up to four weeks after limping out with a hamstring injury against the Brewers.
Ben Thompson, so impressive in his past two games, is likely to start in a holding-midfield role against Stanley, while Gareth Evans is set to resume his duties in the no10 position.
Here are the pros and cons of each of them being recalled by Pompey boss Kenny Jackett.
The academy graduate has been confined to the substitutes’ bench for the past three matches, managing only 17 minutes in total.
Nevertheless, Close is held in high regard by his manager and has made 13 appearances so far this term.
Of Jackett’s options, the Southsea talent has played by far the most football in central midfield this season.
Close has featured in games where Jackett felt the need to keep the ball better.
With Accrington flying in fourth spot, and winning their past four home games, it’s likely they will have spells of dominance on their own patch.
When Pompey do win possession, keeping hold of the ball will be key and Close’s intelligent distribution would help.
The 22-year-old isn’t a natural defensive shield and, by his own admission, says he’s working on his tackling ability.
If Close starts, it will mean Ben Thompson will have to screen the Blues' rearguard.
That would be a waste of the Millwall loanee’s attacking prowess, though, and would limit his opportunities to drive at the opposition.
The ex-Spurs man started Pompey’s season-opener over Luton in central midfield alongside Naylor.
Walkes was withdrawn on 60 minutes for Close, though, and hasn’t featured in the engine room in his subsequent nine appearances.
Walkes’ best performances last term when on-loan from Spurs came when he was playing in a holding-midfield role.
In the 1-0 victory at Walsall, he screened the defence and stuck closely to Saddlers talisman Erhun Oztumer.
The Turk had little room to manoeuvre and lacked his usual creativity.
Walkes was handed similar responsibilities to nullify Nick Powell when Wigan visited Fratton Park.
Having ran amok against most sides for last season’s League One champions, the former Manchester United playmaker offered little attacking threat against Pompey.
That was mainly down to another superb man-marking performance from Walkes.
While Walkes has refused to pigeonhole himself in one position, he’s slightly out of practice playing in the middle of the park.
His primary focus has been at right-back – the role Jackett regards as his best.
Therefore, it may take Walkes some time to acclimatise in the engine room.
If that’s the case, Accrington could take advantage while the former Atlanta United player is getting his bearings.
It was always going to take an injury or a suspension for the fans’ favourite to be given his chance this season.
Rose has continued to work hard in training to try to impress his manager and he may be handed an opportunity at Accrington.
Experience is the significant advantage Rose holds over Close and Walkes.
Moreover, the 30-year-old’s form last campaign highlights he certainly has the nous and know-how to replace Naylor.
Rose was key during the Blues’ most impressive period last term before the turn of the year.
Jackett’s men delivered seven wins in nine appearances, ensuring Pompey ended 2017 in the play-off places.
However, Rose suffered a season-ending leg break against Northampton and his presence was noticeably missed afterwards, with the Blues missing out on a top-six spot.
Rose has very much been on the periphery of things this season.
The former Oxford United man has featured just three times to date, with only one coming in League One.
That was a substitute appearance in the 2-1 win at Blackpool – a game where Rose looked short of competitive minutes.
He has impressed on Checkatrade Trophy duty and for the reserves, but playing against fourth-placed Accrington is a significant step up for those contests.
The former Swindon skipper is again available for duty following the birth of his son on Tuesday.
If there’s one candidate to try to imitate Naylor’s game then it’s Nathan Thompson.
The 28-year-old is dogged, combative and wears his heart on his sleeve.
Thompson featured in central midfield on several occasions after Rose's injury last term, and generally did a decent job.
Gareth Evans regards Thompson as Pompey’s best one-on-one defender – and that attribute will be key against Accrington.
Left-midfielder Sean McConville has been Accy’s talisman this term, registering six goals and three assists.
If the former Chester man is neutralised down the left flank then it’ll significantly thwart the home side’s goal threat.