The United States' preparations for next summer's World Cup got off to a shaky start with a uninspiring display in a 1-1 draw with Scotland.
A bright start was rewarded by Josh Wolff's ninth minute penalty but the good work was cancelled out by Hearts defender Andy Webster, who headed in an equaliser for the Scots eight minutes before half-time.
The Americans displayed some neat approach work, particularly in the wake of their early goal and enjoyed marginally the better of the few chances generated by either side.
But in the absence of first choice strikers Brian McBride and Landon Donovan, they failed to consistently unsettle opponents 55 places below them in FIFA's rankings and it was the Scots, underlining their recent improvement under Walter Smith, who looked the more likely winners at the end.
On this evidence, the United States will struggle to match their achievement at the last World Cup, when Bruce Arena's squad reached the last eight in Japan and South Korea.
Both goals were the result of sloppy defensive work, with the Americans going ahead after being gifted possession by Graham Alexander's slack pass out of defence.
The five-man Scots back line was caught on its heels and their disarray was exposed by Wolff's deftly-angled pass into the area.
As DaMarcus Beasley raced to meet it he was bundled over from behind by Christian Dailly for a clear-cut penalty that Wolff tucked confidently into the bottom corner.
The sanction for the Scots might have been more severe. Dailly's challenge looked clumsy rather than calculated but, given Beasley's scoring position, it might have earned him a red card in a competitive international.
Scotland had another let off in the 16th minute when a Jonathan Spector free-kick bounced awkwardly in front of Craig Gordon and the Hearts goalkeeper did well to turn it round the post.
By the time half an hour had elapsed, the Scots had failed to muster a single effort on goal, but they suddenly produced an equaliser from the most traditional of recipes.
Neil McCann won a free-kick close to the left touchline, Alexander punted the ball into the area and Andy Webster outmuscled his marker, Brian Ching, to send a header beyond Keller.
Wolff should have restored his side's lead three minutes before the break but screwed his shot wide from 15 yards after being teed up by his striking partner Brian Ching's cutback from the left of the area.
Twice in the opening minutes of the second half, Beasley found himself in space inside the Scots area, but the PSV Eindhoven midfielder failed to produce a shot on target from either opening.
The introduction of Everton winger James McFadden sharpened Scotland's attacking edge in the closing stages but the closest they came to a winner was when substitute defender Gary Caldwell tried his luck from 25 yards, his effort narrowly clearing the bar with Keller well-beaten.
Gordon pulled off a good save to keep out a fierce drive from Spector in the dying seconds while an offside decision denied Hibs midfielder Scott Brown what would have been an injury-time winner for Scotland.
Scots and US draw at Hampden
