Engvall had been training with Swedish side Djurgardens ahead of a proposed loan move but has had to come back to boost Johnson's forward options.
The Robins have been stretched in that area, with Tammy Abraham just returning from a thigh strain while Milan Djuric will miss three to six weeks after undergoing a hernia operation.
Goalkeeper Fabian Giefer could be restored to the starting line-up. Giefer was named on the bench against Wigan last weekend after recovering from an eye injury.
Huddersfield head coach David Wagner is likely to choose from an unchanged squad as he has no new injury or suspension problems.
Defender Tareiq Holmes-Dennis returned to training this week and has an outside chance of being in contention.
Forward Harry Bunn is still out following a recurrence of a groin problem and midfielder Kasey Palmer (hamstring) also remains sidelined.
Winger Sean Scannell is still not ready to feature after a long-term ankle injury as Town chase a third straight league win.