Dortmund play Spurs at home next Tuesday needing to overturn a 3-0 defeat from the first-leg at Wembley to have any chance of advancing from the last 16 of the Champions League.
They also need a win at Augsburg on Friday in the Bundesliga title race as they only hold a three-point lead over defending champions Bayern Munich.
“He will probably be involved, but we have to wait and then ask the doctor,” Dortmund head coach Lucien Favre said on Wednesday.
“He’s back in team training, today (Wednesday) was his second session, but whether he will be back in the (matchday) squad, I can’t yet say.”
Reus, who has scored 13 goals in 19 league games this season, has been sidelined for nearly four weeks by a thigh injury.
During his absence, Dortmund failed to win in three games, only breaking the run with a 3-2 victory against Bayer Leverkusen last Sunday when England winger Jadon Sancho starred.
Dortmund will be without wing back Lukasz Piszczek, who has a foot problem, at Augsburg, but US midfielder Christian Pulisic is expected to be fit again after recovering from a leg injury.
Favre says he is grateful for a three-day break before Dortmund take on Spurs.
“The schedule is OK, the three days in between are of course important, but we are just concentrating on the next game,” said the Swiss.
Dortmund will have learnt from Bayern’s experience after Niko Kovac’s star-studded side came from behind twice to seal a 3-2 win at Augsburg — also on a Friday — a fortnight ago.
Favre also said that Spanish striker Paco Alcacer could feature again after making his comeback from a shoulder injury at Leverkusen.
Bayern are at Borussia Moenchengladbach on Saturday looking to avenge a shock 3-0 defeat at Munich’s Allianz Arena when the sides met last October, but Favre insists his side will only worry about themselves.
“We want to stay true to our philosophy, one game at a time — full concentration on the next game – that’s the most important match,” added Favre.
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