Portugal all but sealed a berth in the UEFA Nations League quarterfinals with a 0-0 draw away to Scotland on Tuesday, the first points Roberto Martinez's men have dropped in their four games.

The Portuguese stay on top of Group A1 with 10 points, three ahead of Croatia, who drew 3-3 away to Poland, while the Scots sit at the bottom with one point. The third-placed Poles have four points, with the top two in the group moving into the last eight.

Martinez said his men were missing "a bit of magic in the area."

"We had a lot of desire, we worked very well without the ball," the Spanish coach told Sport TV. "It was a dangerous game because we could have had possession, but Scotland needed very little to score a goal. We showed freshness, but we lacked freshness in the final third."

Portugal were on the front foot for most of the night, but squandered several chances, including a sitter early in the second half for Cristiano Ronaldo, who had scored in their previous three games. Unmarked in the box, he sent a diving header over the bar.

Ronaldo, 39, earned another ironic cheer from Scotland's "Tartan Army" when he sailed a bicycle kick wide.

Asked if Portugal lacked a Plan B, Martinez said: "Our talent, our players, is plan A, B, C, D, E. We have players on the inside, on the outside, we're talking about a team that didn't take risks, that defended very well. We're talking about a team (Portugal) that got into the final third 53 times. We have to give credit to Scotland, and to ourselves, for managing to keep a clean sheet."

The hosts also had chances on a night when they were plagued by careless turnovers, as Scott McTominay narrowly missed with a header before the game was five minutes old.

Ben Doak laid the ball back to Andy Robertson and the captain found the unmarked McTominay with a pinpoint cross, but the midfielder headed it straight at goalkeeper Diogo Costa.

Scotland's goalkeeper Craig Gordon made a handful of terrific saves in the dying minutes against a swarming Portugal side.