With the return of cobblestones and three punishing summit finishes scheduled for the 2010 Tour de France, seven-time champion Lance Armstrong called the 2010 Tour de France difficult and wide open.

"I think it will be much more open than last year because the TTT (team time trial) really eliminated some people last year and you won't have that again," Armstrong said Wednesday after next year's route was announced. "Whereas this year you had three or four guys who could win the Tour, this year you'll go into the tough sections with 10 guys."

The inclusion of some of the infamous cobblestone sections that make up the Paris-Roubaix classic will be especially destabilizing in the race's early stages, the 38-year-old Texan said.

"I think the first week is potentially complicating for guys, with the wind and the mix of the Ardennes and also the cobblestones," said Armstrong, who finished third this year following three weeks of intense rivalry with then-teammate and eventual winner Alberto Contador. "It's a very untraditional start to a Tour. It's going to be a hard Tour."

The first complicated bit for the peloton will come in the race's third stage on July 6. Riders will speed over seven cobblestone sectors with a total distance of 8.2 miles. The last time Tour riders have faced that dangerous task was in 2004.

The cobblestones will weigh heavily on Armstrong's decision on which races to include in his pre-Tour preparations, he said. The Tour of Flanders and Liege-Bastogne-Liege in Belgium are races he is considering entering, Armstrong said.

"I think you have to plan your season according to what you see here, too," Armstrong said. "I think even a race like the Tour of Flanders is interesting now because you don't want your only cobblestone experience to be the day you show up here. You need to practice that so we'll build the season around this, too."

The race organizers' decision to stage only a single individual time trial, a 32-mile race through the Bordeaux vineyards in the penultimate stage, could work in the American's favor.

"Based on my time trials this year I have to be glad there's less," said Armstrong, who finished 90 seconds behind Contador in last year's time trial in Annecy, and 22 seconds behind the Spaniard in the shorter time trial at the race's start in Monaco.

"That last TT is 51K and the day before Paris is going to be decisive."

Armstrong, who came back to competition this year following a 3 1/2-year retirement, said Luxembourg brothers Andy and Frank Schleck and British rider Bradley Wiggins, as well as Contador, were among his toughest potential rivals next year.

Armstrong, who had lunch with French president Nicolas Sarkozy on Wednesday, said he is still considering whether to compete in the Tour of California or the Giro d'Italia, races that conflict on the calendar in May.

"I still don't know. There's more things that factor in there, too, RadioShack being an American company and California obviously being an American race," Armstrong said, referring to his new team.

One race that likely won't figure in Armstrong's Tour preparations is the Milan-San Remo, the spring classic he used to stage his comeback to European racing this year, finishing in 125th place.

"I think I have another appointment that day," Armstrong joked. "A doctors appointment or something, a dentist appointment."