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INTER COULD AFFORD TO DRAW one of their final six Serie A matches and successfully defend the title. For large parts of Sunday's match against Bologna, they seemed happy enough to use their lifeline.

Inter had just lost Marcus Thuram to injury, and his backup, Marko Arnautovic, wasn't fit to start. Head coach Simone Inzaghi had no choice but to trust Joaquin Correa — a €33-million disappointment who's scored just four league goals in the last three seasons — to fill the void.

The Nerazzurri had successfully navigated a string of injuries up until this point. But they couldn't put on a brave face anymore. They looked tired and out of ideas against an energetic Bologna side that's lost just two of its last 20 games. Riccardo Orsolini's 94th-minute scissor kick hit Inter right when they thought they'd escaped the worst. Instead, they trudged out of their 50th game of the season level with Napoli on 71 points.

Antonio Conte's side has played 14 fewer matches this season but faces its own struggles to stay fresh. It could only beat Monza, Serie A's last-placed whipping boys, by a single goal the day earlier. Napoli have an easier schedule ahead — 10th-placed Torino are the highest-ranked side left on their fixture list — but haven't necessarily had an easy time against teams they're supposed to beat.

Both title rivals have their limitations. You could say Inter have more experience, and that Napoli have a better manager, and that Inter have a more complete squad, and that Napoli have kinder opponents, but in the end, there's not much that separate these imperfect sides. The top two teams in Italy aren't exactly the best we've seen in years, but they're some of the stickiest. Inter have gotten results whether they've played well or poorly, and while Napoli have dropped points, blowing leads against Inter, Roma, Udinese, and Bologna, they've limited themselves to just four losses in Serie A.

That Inter are even in contention for the treble is impressive. They have the oldest squad by average age in Serie A and have used a league-low 25 players this season. Quality of depth trumps quantity here. Yann Bisseck is starter material, capable of challenging Benjamin Pavard for minutes. Carlos Augusto has played in both defensive and wide positions. Arnautovic has scored more Serie A goals than he's started games. Davide Frattesi is a high-energy substitute who can do a bit of everything in midfield.

Inter haven't gone more than two games without a win. Napoli recently went winless in five despite playing once a week. That's remarkable consistency, to say nothing of the 13-match unbeaten streak Inter were on before the loss to Bologna.

Now, though, the pursuit of greatness is taking its toll. Inter play in three competitions over the next week or so and could either boost their chances of winning the treble or lose their shot at history altogether. They enter Wednesday's Coppa Italia semifinal second leg against AC Milan level on aggregate, host Claudio Ranieri's resurgent Roma three days later in Serie A, and travel to Barcelona for the first leg of their Champions League semifinal the following Wednesday. Thuram and injured right-back Denzel Dumfries could miss all three. A number of players, including Nicolo Barella and Alessandro Bastoni, are also a booking away from suspension in Serie A.

It would be a catastrophic failure if Inter end up trophyless after the season they've put together. But the possibility feels real, more so than at any other point of the campaign. Inter haven't kept a clean sheet in seven matches, and seem to concede every time Inzaghi substitutes Bastoni. Yet he continues to sub out his best defender as games hang in the balance. Squad rotation can't come at such a great cost.

This is Inter's delicate dance. Inzaghi is damned if he does something and damned if he doesn't. It's why trebles are so hard to win. Every decision has to work out. Let's see how many Inter get right.

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