Roma still has a very good chance of finishing in the fifth position but for that to happen Lazio needs to lose otherwise Roma will not be able to get past them.
Roma has two matches left in the season and they are against Venezia and Torino. I believe Roma will win easily against Venezia but against Torino, it will be hard. On the other hand, Lazio has 2 matches against Juventus and Verona. So I believe Roma has a good chance because I don't see Lazio winning both the matches that are left.
facing Juve will not be easy for Lazio. Lazio's previous meeting had to lose at home 0-2. if Roma gets full points from the last 2 matches, I think Roma's chances of finishing in 5th place are very big.
on the other hand, Lazio also can be displaced by Fiorentina or Atalanta. The fight for tickets to get into the top 6 of the current standings is very interesting.