Reports in Italy claimed on Sunday night's 3-1 victory over Inter Milan could have been Reja's last game in charge, with the 66-year-old yet to sign a new deal with his current contract ending this summer.
"We will have a meeting with Reja in the next few days and make a decision," Lazio sporting director Igli Tare said to Corriere dello Sport.
"We must thank Reja for all the work he has done."
Lazio missed out on a third-place finish in Serie A after ending the campaign on 62 points, two adrift of Udinese.
Reja replaced Davide Ballardini at the helm of Lazio in 2009 and guided the team out of the relegation zone and into a mid-table finish.
Lazio, who finished fifth last term, will have to settle for Europa League football for the second consecutive season as Udinese will be playing in the Champions League preliminary round.
"Unfortunately, in the crucial stages of the season we lacked good fortune," Tare said.
"Next season we will try to be as competitive as we have been this term."