Former Scotland lock Jim Hamilton has backed Gregor Townsend's decision to drop Finn Russell for Saturday's Six Nations game against Ireland, saying "it is maybe the rocket he needs".

Scotland coach Townsend and Racing 92's Russell, 29, fell out at the start of the 2020 Six Nations and he only returned for the 2021 championship.

"It's a massive call but it feels like the right call," Hamilton said.

"I feel awful saying that because I love Finn. I love what he's done for Scottish rugby. I love his character," Hamilton told RugbyPass.

"But he's struggled for the last few games, he doesn't look himself. We knew about the relationship with Gregor and thought we had got through that but Finn's discipline has been an issue in recent games.

"It shows he isn't 'not droppable'. There's one player that is undroppable and that's Stuart Hogg.

"With 'Hoggy' you are getting a seven, eight, nine, 10 out of 10 performance. Every single game. With Finn you're getting a 10 out of 10, or a six out of 10. The last few games we've been seeing six out of 10s.

"We need to know with the Rugby World Cup, we've got another player who can play fly-half even though I didn't see Blair Kinghorn as a 10," added Hamilton, who played 63 times for Scotland.

Russell played well in the opening-weekend victory against England but has been ineffective in the three games in the Six Nations since then, two of which have been lost.

Edinburgh's Kinghorn, 25, a full-back until this season, starts a Six Nations game in the number 10 shirt for the first time.

Townsend said playmaker Russell was "initially disappointed" when told of his omission for the game in Dublin, but will "support the team and Blair".

"I prefer to focus on what Blair has done and how well he's played," added Townsend. "He has deserved this opportunity with his performances throughout the season.

"He's been in really good form. He wasn't available for our match last week but the week before that he played his best game of the season against Connacht."

Second-row Gray replaces Exeter colleague Sam Skinner in the only other change to the starting XV from last week's win in Italy, although hooker Fraser Brown returns to the bench.

Townsend's men lie fourth - level on points with third-place England - after two wins and two defeats.

Scotland have not won in Dublin for 12 years, while Ireland need victory - and England to beat Grand Slam-chasing France in Paris later on Saturday - to claim the title.

Scotland: Hogg; Graham, Harris, Johnson, Steyn; Kinghorn, Price; Schoeman, Turner, Z Fagerson; Gray, Gilchrist; Darge, Watson, M Fagerson.

Replacements: Brown, Dell, Nel, Skinner, Bayliss, White, Russell, Bennett.

Hamilton is one of the guests on the Rugby Breakfast Show live on BBC Radio Scotland and the BBC Sport website and app from 10:00 GMT on Saturday