The Baggies fell to defeat at QPR last weekend with a host of players missing at centre-halve.
Bartley missed out with an ankle knock, Cedric Kipre was suspended, Semi Ajayi is currently away at the African Cup of Nations while Dara OShea has only just returned to training following surgery on a broken ankle. Those absentees led to wing-backs Darnell Furlong and Conor Townsend being shifted to centre-back at Loftus Road.
Bartley, though, is expected to be back for the visit of Darren Ferguson’s side on Saturday – with the defender initially hurting his ankle against Brighton on January 8.
“We will get two players back for Peterborough (Kipre and Bartley) that will give us options in the centre-back position,” Ismael said.
“Normally the injury (Bartley’s ankle) is seven to 10 days so we hope he comes back next week to have another possibility.”
Despite Bartley and Kipre returning, Albion will be missing suspended duo Sam Johnstone and Alex Mowatt for the Posh game.
And Ismael says their long list of absentees is the reason why they have won just twice in their last 10 outings.
“Cedric Kipre and Kyle Bartley will be back but we need every player, a strong team and a strong bench,” the boss said.
“We will miss another two players (Johnstone and Mowatt) through suspension.
“This season – with injuries, with Covid, with suspensions we never have the possibility to play week-in, week-out with all of our key players out there.
“This is what we have had to manage for months now.”
Meanwhile, Albion Josh Griffiths will remain on loan at Lincoln City for the remainder of the season, Imps boss Michael Appleton has confirmed.
Speaking earlier this month, former Baggies coach Appleton said he wasn’t sure if Albion would activate their recall for the England under-21 goalkeeper.
“We’ve not heard from them (Albion) and the deadline has passed so he will be with us for the rest of the season,” Appleton said.
“He’s got stronger and stronger. His performances have grown and he’s improved with his feet as well.”