The 35-year-old was a late withdrawal from the final Ashes warm-up match and is now facing a battle to prove his fitness for the opening Test against England which starts in Cardiff next Wednesday.
Harris struggled with knee soreness following the first tour match against Kent last week, and was replaced in the Australians XI at the Essex County Ground by Peter Siddle.
Australia coach Darren Lehmann had indicated the four-day match in Chelmsford was key for Harris’ hopes of being involved at Sophia Gardens ahead of the likes of Mitchell Starc, Josh Hazlewood and Mitchell Johnson
“At the end of the day, Ryan Harris has got to be fully fit and if he’s doing that then he’s a big part of our side or squad going forward,” Lehmann said after the win in Canterbury on Sunday.
“He has got to prove to us he can bowl 20 overs in an innings or roughly about and make sure he’s ready to go. If he can do that, he certainly comes into consideration.”
Reserve wicketkeeper Peter Nevill started for Australia against Essex, while opener David Warner, Starc, Hazlewood, Nathan Lyon and Adam Voges were all given run-outs in changes from the side which beat Kent by 255 runs at the Spitfire Ground.