Walcott made his return from a serious knee injury against Burnley on Saturday, coming on as an 80th-minute substitute in the 3-0 win to end a nine-month absence, but did not feature in the midweek 3-3 draw with Anderlecht.
Nevertheless, Hodgson has seen fit to include the 25-year-old in his 26-man party for the upcoming double-header, with Walcott joining West Brom youngster Saido Berahino in the squad.
Berahino has enjoyed a stunning season to date, scoring eight goals in 13 appearances in all competitions so far, and the 21-year-old, who was born in Burundi, will provide competition to fellow strikers Rickie Lambert, Wayne Rooney and Danny Welbeck.
Downing, meanwhile, returns to the England fold, having played a key role in West Ham's rise into the top five. The winger, who has earned 34 caps, last featured under Hodgson in the 1-0 win over Norway on May 26, 2012, but will join the likes of Alex Oxlade-Chamberlain, Raheem Sterling and Andros Townsend in providing a wide option for the 67-year-old.
Elsewhere, Nathaniel Clyne retains his place in the squad, as does Calum Chambers, while Michael Carrick returns after an enforced absence through injury.
England squad in full:
Goalkeepers: Joe Hart (Manchester City), Ben Foster (West Brom), Fraser Forster (Southampton)
Defenders: Leighton Baines (Everton), Gary Cahill (Chelsea), Calum Chambers (Arsenal), Nathaniel Clyne (Southampton), Kieran Gibbs (Arsenal), Luke Shaw (Manchester United), Phil Jagielka (Everton), Chris Smalling (Manchester United)
Midfielders: Ross Barkley (Everton), Michael Carrick (Manchester United), Stewart Downing (West Ham), Jordan Henderson (Liverpool), Adam Lallana (Liverpool), James Milner (Manchester City), Alex Oxlade-Chamberlain (Arsenal), Raheem Sterling (Liverpool), Andros Townsend (Tottenham), Jack Wilshere (Arsenal)
Forwards: Theo Walcott (Arsenal), Rickie Lambert (Liverpool), Wayne Rooney (Manchester United), Danny Welbeck (Arsenal), Saido Berahino (West Brom)
