Laidlaw, who was a member of the Lions squad in 2017 that featured Sexton and, briefly Russell, cannot envisage a situation where his former Scotland team-mate misses out on selection for Farrell’s squad.
“Finn’s definitely going to be on that tour, I would believe,” Laidlaw told BBC Scotland.
“I think he’s going to get himself there on merit. He’s been excellent, went on the last tour, played really well in the third Test.
“He’s a quality player, he’s been in excellent form for Bath as well, flying high in the Premiership.
“When you look at that coaching staff now with Jonny Sexton, Richard Wigglesworth, I think it lends more to them also including Owen Farrell. I could probably see that happening.
“If that happens, I still see Finn going as well, probably those two plus Sam Prendergast as well. So I can’t see why he’s not going to be in the squad.”
Laidlaw got a close look at Sexton on that 2017 tour to New Zealand and believes he could work with Russell despite their contrasting personalities.
“Sexton was the ultimate competitor,” said Laidlaw, who is coaching in Japan with Urayasu D-Rocks.
“I had the privilege of sharing some time with him on that trip and I certainly learned a bit off him.
“He’s just a different person to Finn. He’s obviously more serious. He’s just completely different.
“Hopefully now that he’s obviously not playing, some of that stuff will waver away and surely they can put the differences to one side and hopefully get on with each other.”