London Scottish boss Simon Amor has been working on his side's defence in the aftermath of the heavy defeat to Bedford.
Having won their opening game of the season, the Exiles followed their spirited 49-32 loss to title favourites Newcastle with a 55-20 thumping by the Blues.
And having shipped 104 points in the past two games, Amor is keen to tighten things up against Doncaster at The Athletic Ground on Saturday.
Amor told the club's official site: "Rugby is a simple game; if you miss one-on-one tackles you will lose matches and we missed far too many in that game.
"With that in mind, defence has been our prime focus this week and we are looking to adapt and progress our system.
"We know our defence will have to be at its very best to counter what is a very physical and very strong Doncaster team."