In his column for The Sun, Anderson said he is trying to regain maximum fitness ahead of England's upcoming assignments, which include tours of New Zealand and South Africa, followed by a home series against West Indies.
Australia retained the Ashes with victory in the fourth test at Old Trafford, where Smith continued his brilliant series with a double-century and a second innings 82.
However, Australia's first Ashes retention on English soil since 2001 was a triumph for Paine, who was credited for helping guide the side out of the dark days that followed the ball-tampering scandal.
England seamer Craig Overton was also dropped.
Although he did show some grit to fight it out on the final day of the Old Trafford Test, the fact that all-rounder Ben Stokes won't be available to bowl due to a shoulder injury seems to have gone against him as the selectors looked to strengthen the bowling line-up, drafting in the left-arm swing bowler, Sam Curran.
Root's captaincy, and his form, has come under the spotlight but he sounded an upbeat tone as he looked forward to trying to level the series.
England can not win the Ashes as they head to the Oval 2-1 down for the final Test.
Root has made three ducks in the series and averages 30 but played down suggestions his batting had suffered because of being captain. I think the Australian team have bowled pretty well to him.
"It's bitterly disappointing to not have got the Ashes back, but we haven't lost anything yet", he said.
"But ultimately we need to focus on the core group of players that are going to lead this team forward both home and away and build from that and towards winning in Australia".
"We've already spoken a lot about it (the final Test)", Paine said Wednesday on the eve of the match.
"You've still got to perform whether you're young or you're a veteran, but we also have to recognise they are young batsmen and it's a really tough school and hopefully they'll come through at some point".
Paine said Marsh's inclusion was aimed at easing the workload on his impressive pace attack and that he had "full faith" in his batting.
Peter Siddle, who played the first two tests, has been retained in a 12-man squad and could be recalled in place of the world's top-ranked bowler Cummins or an in-form Hazlewood.