Is Tadej Pogaars closest challenger at the Tour de France his own UAE Team Emirates-XRG teammate Isaac del Toro?The 22-year-old Mexican is making his debut in the French Grand Tour, and apart from Pogaar he has arguably been the most impressive rider so far. Hes also currently in the white jersey as the best young rider.He posted the sixth fastest-time on the first day team time trial; won the second stage on Montjuc in Barcelona; teed Pogaar up for victory the following day; and then set up his teammates attack on the Col du Tourmalet on stage six. Despite putting in a lung-busting effort, Del Toro stuck with the other podium contenders and eventually finished third in Gavarnie-Gdre.Ahead of stage seven, he is in third place, 3:27 off Pogaar in yellow, and 45 seconds adrift of Vingegaard. Six riders are within a minute of Del Toro; the battle for the podium looks set to be more intriguing and unpredictable than the race for yellow.The way Del Toro outsprinted Vingegaard on Montjuc and then rode him off his wheel on the Tourmalet has indicated that the Pogaar-Vingegaard duopoly of positions one and two at the Tour stretching back to 2021 may be under threat.Hes here to work for Tadej, UAE Team Emirates-XRG manager Mauro Gianette told Cycling Weekly at the end of stage six. It depends how much he will need to do a job for Tadej [if he can challenge for second place], how necessary that will be.But of course hes in great, great shape, hes progressing, and hes an amazing champion. Hes just here to discover the Tour and I hope he can stay at the front everyday because thats how hell best discover the Tour.Gianetti refuted the suggestion that Del Toro had the legs to ride with Pogaar over the top of the Tourmalet. No, no, he could not stay with Tadej, he said. He tried for one moment because Tadej asked him to go with him, but he had a very hard five minutes. He had to do the last 200 to 300m full gas before Tadejs attack and that cost a lot of energy.He recovered again and he did very well. Isaac is in very good shape and were so happy with him.Though there is already talk of the Tour being done and dusted three stages before the first rest day, Gianetti, as would be expected, refused to countenance that idea.Of course were in a good position, but its still long weve only done six stages, Gianetti said. We need to take it day by day and stay concentrated. Jonas is Jonas and hes a very strong rider. He will not give up.