Johnny Sexton says Ireland must prevent his opposing fly-half Finn Russell from producing his "full box of tricks" in their Six Nations clash against Scotland on Sunday. The Irish skipper masterminded two wins over the Scots last year but both times Russell was absent. Ireland go into the match in Edinburgh after their first win of this year's tournament -- a 48-10 thumping of Italy -- but Sexton said the Scots would be a "big step up". Scotland beat England at Twickenham last month for the first time since 1983 before losing narrowly to Wales when they were reduced to 14 men. "He (Russell) is obviously a big threat for us, knowing he has a full box of tricks he tries to pull out in most games," Sexton said on Wednesday. "He is a threat to the line and has a good short kicking game, he can pull the strings if we let him. He has hurt us in the past and he did not play in our two wins over them last year. "He is a massive threat -- one of many across the team but him and Stuart Hogg are the standout guys." Sexton said Russell and Hogg brought world-class panache to the Scotland team but credit must also be given to head coach Gregor Townsend and his backroom staff. "But for a tap tackle towards the end of the game with Wales they could still be on course for the Grand Slam instead of the Welsh," he said. "They are full of confidence and will fancy themselves against us. We have massive respect for them as a team and they are a really well-coached team as well." Sexton put immediate speculation over his future to rest by signing a one-year extension to his contract last week. He said nothing should be read into the length of the contract, with others such as lock Iain Henderson and flanker Peter O'Mahony signing two-year deals. "I am at an age like most guys in their mid-30s that a year is suitable," he said. "It lets you see how you are feeling next year and also performing and one can reflect on that when the time comes." He added: "I am hungry still for success with both Leinster and Ireland and that is what my team-mates see on the training pitch. "That is what means the most to me." The British and Irish Lions Test series against world champions South Africa is scheduled to take place later this year but Sexton said that was still at the back of the Irish players' minds. Sexton has been a pivotal part of coach Warren Gatland's previous two tours -- a series win over Australia in 2013 and an epic drawn series with then world champions New Zealand in 2017. With England's Owen Farrell and George Ford's form faltering, Sexton could be competing with Russell and perhaps one of Wales pair Dan Biggar and Callum Sheedy for the fly-half spots. "It is not at the forefront of our minds," he said. "Winning our two final games (against Scotland and England) of course puts our best foot forward. "It is in the back of our minds that the Scotland game is pretty important in terms of Lions selection. A couple of wins and we get more Irish bodies on the plane." pi/jw/dmc