The 29-year-old centre-back joined the Shrimpers on a free transfer until the end of the season from Colchester on Friday and could slot straight into the heart of defence.
Baldwin previously spent time on loan at Roots Hall during the 2009/10 season when he made 18 appearances. Manager Paul Sturrock does have two injury concerns as his side bid to return to the summit of the npower League Two table.
Defender Mark Phillips is battling a groin problem while midfielder Jean-Paul Kalala is struggling with a hamstring strain. The pair had to come off in the Shrimpers' 2-1 defeat to Shrewsbury and will be handed late fitness tests with Sturrock mindful of forthcoming clashes with Plymouth and Rotherham.
Swindon will be without injured centre-back Aden Flint. Flint, who has impressed at the heart of the the Robins' defence this season, has a groin problem which kept him out of the 2-0 FA Cup fourth-round defeat to Leicester on Saturday.
Meanwhile, forward Billy Bodin may not be included in the matchday squad, with the Wales Under-21 international set to leave the County Ground before the January transfer window closes on Tuesday night.
Striker Mehdi Kerrouche will not feature for manager Paolo Di Canio.
The Algerian has not played since the 1-1 draw at Bristol Rovers on December 10 and the Wiltshire club hope to offload him before the window slams shut. Luke Rooney is available to Di Canio once again after the winger was cup-tied for the trip to Leicester.
Southend V Swindon - view commentary, squad, and statictics of the game live.
Source: PA
