The 52-year-old says every game is giving him a greater insight into the quality of his players as he decides who will stay at the club in the summer
Following their stalemate at the Olimpico, the Nerazurri sit in fifth place in Serie A, having lost just one of their last six Serie A matches, a 3-1 defeat to league leaders Juventus.
However, Mazzarri, who arrived at the club in May 2013, says that his players must continue to impress as he assesses the strengths and weaknesses of the team ahead of next season.
"This year is for me to assess the squad. The lads have to prove themselves and every match provides extra info," Mazzarri told Sky Italia.
"We'll add everything up at the end then look at who stays and all the rest of it. Our target for the moment is to finish as high as possible."
Despite their recent form, Inter have drawn four of their last eight Serie A matches, but Mazzarri claims they have been unfortunate not to pick up more points in their bid for European football.
With Inter occupying a Europa League spot ahead of their final 12 matches, the 52-year-old feels progress is being made from their ninth-place finish last time out.
"If you look at the draws we've had at home recently, they're the sort of games where it only takes one goal to win it, but against Cagliari we hit the bar and there have been games we've dominated with 14 or 15 corners but not been able to win," he added.
"We just needed someone to stick a leg out and poke one home to get the three points, yet in terms of our play the team is doing really well."