Sterling, who has been in fine form for his club this season, pulled out on Monday night through injury, although no details have been given about the extent of it.
Townsend has played 11 times for England and scored three goals since making debut in 2013 but was initially overlooked for Southgate’s first squad, despite a positive start to life at Selhurst Park.
The 25-year-old was also not included in Sam Allardyce’s only Three Lions squad and was left out of Roy Hodgson’s final Euro 2016 squad, despite making the initial group who met up for the pre-tournament warm-up games.
Townsend, who joined Palace in the summer in a £13m deal from Newcastle, has featured in all seven of the Eagles’ Premier League games so far this season and has scored one goal.
Full England squad to play Malta and Slovenia this month:
Goalkeepers: Fraser Forster (Southampton), Joe Hart (Torino, on loan from Manchester City), Tom Heaton (Burnley)
Defenders: Ryan Bertrand (Southampton), Gary Cahill (Chelsea), Phil Jagielka (Everton), Glen Johnson (Stoke), Danny Rose (Tottenham), Chris Smalling (Manchester United), John Stones (Manchester City), Kyle Walker (Tottenham)
Midfielders: Eric Dier (Tottenham), Jordan Henderson (Liverpool), Alex Oxlade-Chamberlain (Arsenal), Michail Antonio (West Ham), Jesse Lingard (Manchester United), Theo Walcott (Arsenal), Dele Alli (Tottenham), Andros Townsend (Crystal Palace)
Strikers: Wayne Rooney (Manchester United), Marcus Rashford (Manchester United), Daniel Sturridge (Liverpool), Jamie Vardy (Leicester)Reuse content