The 34-year-old left-handed opener, who made a hundred on his Test debut, has managed just one century in his last 34 Test innings - 110 in the drawn Ashes opener against Australia in Brisbane in November.
And although England lead Sri Lanka 1-0 in this series, following an innings victory in the first Test in Cardiff, Strauss's return has been a meagre 24 runs at an average of eight.
In the drawn second Test at Lord's - his Middlesex home ground - Strauss was out twice lbw - for four and nought - to left-arm seamer Chanaka Welegedara.
"I was frustrated with my returns at Lord's," Strauss said at the Rose Bowl yesterday - the day before Hampshire's headquarters makes its Test debut.
"But that's the nature of the beast as an opening batsman, sometimes you get a couple of good balls early. I'm very comfortable with my own game and I'm very comfortable with us as a batting unit - six out of seven were in fantastic fettle in the first two matches, now it's my turn to come to the party, no doubt about that."
Strauss has a career average of nearly 43 in 84 Tests with 19 hundreds. He denied the pressures of captaincy were harming his batting, and said: "You can over-analyse these things but I'm not going to fall into that trap. I just need to give myself the best chance of scoring runs."
England welcome back James Anderson after the spearhead of their bowling attack missed the second Test with a side strain.
It appears Strauss's Middlesex colleague Steven Finn will make way even though he took more wickets than the struggling Stuart Broad at Lord's.
Sri Lanka held firm in the fourth innings of last week's second test to earn a draw, but the team's chances of squaring the three-match series may have been compromised by a broken thumb sustained by Tillakaratne Dilshan, their new captain.
Dilshan - who averaged 84.33 in the first two Tests - was ruled out of the match on Tuesday, ensuring in the long term that he will be available for the limited-overs games later in the tour.
"It's going to be a huge blow for them because he is a key player [and] their captain," said Anderson.
Dilshan's place is set to go to the uncapped 21-year-old Lahiru Thirimanne, who scored a century in a warm-up match against county side Essex last week.
That match also saw Kumar Sangakkara, who will lead the team in Dilshan's absence, finally return to form with a timely 153.
Sangakkara admitted he was a reluctant captain, having stepped down as team leader after Sri Lanka's World Cup final defeat by India in Mumbai in April.