When Lopez claimed the lead on the stage 5 summit finish at Javalambre, Roglic moved into second place, 14 seconds back.
Then just like Lopez, Roglic lost two spots overall on stage 6 when Dylan Teuns (Bahrain-Merida) and David de la Cruz (Ineos) briefly assumed an ephemeral command of the GC rankings.
On stage 7, Lopez is back up in the lead again and Roglic, who formed part of the quartet of favourites that opened up a significant gap on Mas de la Costa, is back up into second again.
With a second place on the stage behind Alejandro Valverde (Movistar) and with a six-second gap on Lopez, Roglic halved his gap to the Colombian to just six seconds, meaning that if he comes through the Andorra mountain stage unscathed, the Slovenian will be poised to pounce on the lead in the time trial in Pau.
Roglic was his usual calm, somewhat taciturn post-stage self on Friday, telling a small group of reporters that "it was a hard stage, with a really hard climb again. But our team did a perfect job. We can all be happy."
He was impressed, as he had been on stage 5, by Valverde's performance. On that stage, the Spaniard and Slovenian had matched each other up the Javalambre with Valverde pipping him across the line for fifth and sixth, whilst on Friday, the World Champion was stronger in the sprint for the line.
However, Roglic was in no way downbeat about being beaten by Valverde, saying simply that his plan was on track.
"That was a really extreme ride by Alejandro but so far so good," he analysed. "We'll try to keep going like that."