The Champions League title holders have moved up to third place in the league while Juventus, which won at Cagliari last week and is in eighth place, is also on the upswing.
"We have to continue the improvement we showed at Cagliari against a very confident Inter side," Juventus defender Giorgio Chiellini said. "Winning would give us a huge confidence boost, especially because we would be taking points from a direct rival.
"It is a massively important game for us, both for our place in the standings and for our fans.
We are hopeful of having a good February to make up for the problems and bad luck we had the start of the year." The only loss Inter has under Leonardo was a 3-1 setback against Udinese, but since then the Brazilian has been able to reinforce his side by signing Giampaolo Pazzini, Houssine Kharja, Andrea Ranocchia and Yuto Nagamoto.
Pazzini made an immediate impact by scoring two goals in three games, while Kharja weighed in with his first in an Inter shirt by netting the opener in the 3-0 win over Bari.
"We are delighted with how we've done since Leonardo arrived," Inter goalkeeper Julio Cesar said. "We are on the right path and we have to keep on in this direction.
Pazzini, Kharja and Nagamoto are excellent purchases and since they arrived they've done very well." Also, league leader AC Milan hosts Parma at the San Siro after four draws in its last seven matches.
Despite not winning in its last two games, Milan is unbeaten in seven, leads by three points and has the best defensive record in the league.
"We're first in the league and intend to stay there until the end of the season," Milan goalkeeper Christian Abbiati said. "This is the right mentality to have.
"At the start of the season teams were hitting us on the counterattack, but then we got ourselves organized and if we don't concede any goals, sooner or later we will score." Second-place Napoli faces a big test against AS Roma, which is smarting from a 5-3 loss to Inter last week.
"We know it is an important game and if we get a point there it will be another sign of the growth of this team," Napoli captain Paolo Cannavaro said. "(Jeremy) Menez is very quick and is good at beating his man and we can't forget about (Francesco) Totti, who is a fantastic player.
"It is true that we are starting a run of big games, but we will continue to take things match-by-match and we will treat the game with Roma like a final." Also, it's: Palermo vs. Fiorentina; Bari vs. Genoa; Brescia vs. Lazio; Cagliari vs. Chievo Verona; Catania vs. Lecce; Cesena vs. Udinese; and Sampdoria vs. Bologna.