The coach replaced Vladimir Petkovic on Saturday and will face Walter Mazzarri's men — who have lost once in their last 10 Serie A games — on Rome turf.
The 68-year-old was announced as Vladimir Petkovic's replacement Saturday and will be looking to turn around the club's fortunes after a disappointing run of form that has seen the Biancocelesti win only twice in their last 12 Serie A games.
Reja had an eventful two-year spell as Lazio coach from 2010 to 2012, when he guided the club to a fourth-place finish and into the Europa League.
Inter arrives in the capital on the back of victory over city rival AC Milan prior to the midseason break and Walter Mazzarri's side has only lost once in its last 10 league matches.
That win at San Siro moved Inter into fifth, but the side's recent record against Lazio suggests it faces a tough start to 2014. Lazio, which is 10th, has won the last three meetings between the two teams and four of the last six.
Lazio have also not had any problems finding the net on a regular basis this season, scoring in 13 of their 17 Serie A matches. However, along with Verona, they have conceded the most goals of any of the top 10 sides in the league with 26.
That record does not bode well ahead of the visit of the top-flight's second-highest scorer in Inter, which has bagged 37 goals this season.
Inter midfielder Ricky Alvarez returns from suspension for the match and Diego Milito may also be fit following his thigh problems, but Inter will be without Saphir Taider, Cristian Chivu (both thigh) and the suspended Hugo Campagnaro.
Lazio has injury concerns over Stefan Radu ahead of the clash. The Romanian defender missed training with a muscle problem, but the club is still hopeful he will be able to play some part.
Biancocelesti captain Stefano Mauri is suspended for the clash.