Evans reported a blow to his knee after last Saturday's thumping 4-0 win over Walsall but the issue appears to have improved as the week has progressed.
In other news, Reece Burke has returned to training this week after coming off towards the end of the Walsall game with a minor hamstring problem.
Josh Cullen should also be available for selection against Southend after playing in the Barclays Premier League U21s Cup final first leg for West Ham United at the Boleyn Ground on Monday night.
Parkinson said: "Lee Evans had a slight problem with his knee but he is a lot better today (Thursday).
"We will just monitor that one before the weekend.
"Reece is fine now. He did a bit of running on Tuesday and he has trained fully today (Thursday). We are pleased with how he is.
"Josh has also come back unscathed after his game on Monday."