Frank Lampard hands debuts to defenders Reece James and Marc Guehi and a first start to midfielder Billy Gilmour.
The side is completely changed from the one that started Sunday’s match against Liverpool. Kurt Zouma and Marcos Alonso, who came on during the first half at the weekend, start tonight with 19-year-old James set to take his bow at right-back and Guehi, who is also 19, partnering Zouma in the centre of defence.
Gilmour, who made his Chelsea debut when he came on as a sub versus Sheffield United last month, joins Ross Barkley in midfield while Callum Hudson-Odoi makes his welcome return from injury as part of an attack featuring Pedro (tonight's captain) and Christian Pulisic, with Michy Batshuayi at its spearhead.
There are three players yet to make their debut on the Chelsea bench.
Grimsby have made four changes to their side which won their most recent League Two outing.
Chelsea Caballero; James, Guehi, Zouma, Alonso, Barkley, Gilmour, Hudson-Odoi, Pedro (c), Pulisic, Batshuayi.
Substitutes Cumming, Maatsen, Tomori, Jorginho, Anjorin, Mount, Abraham.
Grimsby McKeown (c); Hewitt, Hendrie, Pollock, Davis, Gibson, Hessenthaler, Clifton, Whitehouse, Green, Hanson.
Substitutes: Russell, Rose, Cook, Wright, Cardwell, Ogbu, Vernam.
The referee is Keith Stroud
Chelsea and Grimsby have never previously met in the League Cup.
Our most recent meeting with the Lincolnshire side was in the FA Cup, back in February 1996 when we drew 0-0 on a freezing night on Humberside and then won the replay 4-1 at the Bridge.
The meeting before the 1996 FA Cup tie was in 1983/84 when Kerry Dixon scored the only goal at Blundell Park on the final day of the season to secure the Second Division championship.
Chelsea are looking to progress to the League Cup fourth round for the ninth successive season.
The last team to defeat us at the third round stage was Newcastle in 2010/11 when they beat us 4-3 in a see-saw encounter. Shola Ameobi scored a stoppage time winner after Nicolas Anelka had equalised from the spot three minutes earlier.
The only other occasions we have been eliminated from the third round since the turn of the century were against Charlton at home on penalties in 05/06, and Liverpool at Anfield in 2000/01.
The last lower division side to knock us out of this competition was Burnley in the fourth round in 2008 on penalties at Stamford Bridge after extra-time. Huddersfield were the last Football League team to beat us in 90 minutes.
Chelsea are looking for our first clean sheet of the season in our ninth match. Our last shut-out was at Leicester in May.