(CNN) -- "Lance Armstrong is over in four or five days," the seven-time champion said Wednesday as he reflected on a gallant failure to crown his Tour de France career with a consolation victory.
The 38-year-old American is riding his final Tour and after his chances of winning the yellow jersey for an eighth time disappeared last week, a stage victory became his target.
His big chance came on Tuesday on the 16th stage which finished in Pau after a series of tough climbs in the Pyrenees.
The RadioShack team leader called on all his experience to drive a breakaway group which eventually swelled to eight riders.
With the race leaders such as Alberto Contador and second-placed Andy Schleck content to ride in with the main bunch, the scene was set for Armstrong to deliver.
Unfortunately, Pierrick Fedrigo of the French Bbox Bougyues Telecom team had not read the script and had too much speed for Armstrong and the other riders contesting the sprint for the line.
Armstrong was chasing a 26th stage victory on his 13th Tour de France appearance, but admitted he came up short.
"It was full gas all day," he told gathered reporters on the rest day.
"I focused on the stage, tried to get up in the moves and it didn't work -- I wasn't fast enough in the end.
"Fedrigo's very fast and he deserved to win."
Armstrong has one further realistic chance of capping his cycling career with a victory on Thursday's 174-kilometer 17th stage from Pau to a summit finish on the feared Col du Tourmalet.
But that will require a superhuman effort with Schleck, who is eight seconds behind Contador, needing to gain back time and likely to launch a series of attacks.
"Eight seconds is nothing in the third week of the Tour," the Luxembourg rider told reporters.
"I think that whoever gets to the top of the Tourmalet first on Thursday will win the Tour."
That is an impossibility for Armstrong, who is 26th overall, over half and hour behind the leaders, but he promised to give his best.
"I'm not the best guy in the race this year, but I still have the spirit of a fighter," he said.
Defending champion Contador, who relegated Armstrong to third place on his comeback to the Tour last year, is bidding for a third Tour de France triumph.