O’Shea had been in a rich vein of form for the Baggies before breaking his ankle whilst playing for the Republic of Ireland in September.
After undergoing surgery, the centre-back was ruled out for between four and six months. But he returned to first-team training this week.
Albion’s under-23s face Villa on Monday, but while that game will be too soon for O’Shea, the clash with Blues on January 24 is a realistic target.
“Dara has made massive progress again,” Ismael said. “He’s back in full training now.
“He needs time. It’s clear that we are all delighted he’s back.
“But he needs a very good week with the squad to get that feeling, to be completely free in his movement, in his skills on the pitch.”
Asked if O’Shea could play for Albion’s under-23s against Villa on Monday, Ismael said: “It’ll be too early. Dara has trained for a few days with the team.
“He needs a good week of team training, seven to 10 days, and then we can go from there.
“If he is able to keep that intensity every day, come back, recover, after that we go from there.
“It will be more likely that one week later he can play for the 23s. That is the plan and afterwards we go from there.
O’Shea’s return is a big boost for Ismael who hasn’t been able to name an unchanged team since October due to injuries, Covid and suspensions.
And the boss believes fans will see a big difference in his side when more players are back.
“It will be good when we can play with our strongest XI every time and to create on-pitch relationships,” Ismael said.
“At the minute, we are not able to do that.
“We have tried to find solutions to these issues and I think we’ve shown a togetherness.
““Our purpose is to make sure we get every player back available as soon as possible to give us the best chance to be as strong as possible.”