Harper, who attracted interest from Premier League clubs over the summer, has taken a full role in training and is ready to return to action after an ankle injury that has sidelined him for the last two fixtures.
But he will struggle to regain a starting place after Steve Coppell's side recorded a hugely impressive win on Tuesday against title rivals Wolves.
Coppell's side have been in imperious form at the Madejski with last Saturday's 4-0 rout of Swansea making it 16 goals in four home games.
Coppell has no fresh injury concerns for the visit of the fourth-placed Clarets, although Marek Matejovsky (knee) Michael Duberry (Calf) and club captain Graeme Murty (calf) remain absent.
Owen Coyle, the Championship's manager of the month for September, will be reluctant to make changes to his Burnley side.
The Clarets recorded a 3-2 home win over Watford in midweek to extend their unbeaten run to nine matches.
Coyle has named summer signing Chris Eagles among the substitutes for the past three games and the former Manchester United man may again be forced to settle for a place on the bench at the Madejski Stadium.
On-loan Sunderland defender Russell Anderson has been ruled out for the season after he damaged knee ligaments during last week's Carling Cup victory over Fulham.
Ade Akinbiyi and Kevin McDonald could again miss out due to injury but Coyle has no other concerns as his men seek to topple the third-placed Royals.