Watford travel to the New Den with one eye on their Premier League game against Arsenal on 31 January, as the likes of Troy Deeney and Etienne Capoue are on the bench. The hosts, though, hammered Premier League club Bournemouth in the third round.
Millwall: Archer, Cummings, Webster, Cooper, Craig, Onyedinma,
Thompson, Williams, O'Brien, Gregory, Morison.
Subs: Martin, Worrall, Romeo, Wallace, Ferguson, Abdou, King
Watford: Pantilimon, Mariappa, Kaboul, Britos, Dja Djedje,
Guedioura, Watson, Mason, Doucoure, Sinclair, Okaka.
Subs: Gomes, Prodl, Cleverley, Deeney, Cathcart, Janmaat, Capoue
The FA Cup match between Millwall and Watford is live on talkSPORT 2 at 12pm on Sunday 29 January.