Two fifteen year olds, Will Greenidge and Josh Akotcha, will be handed a chance to impress in a game although the Hammers cannot now advance to the later stages.
However, Benfica can, and that means the youngsters will be put to a stern test.
Westley told CandH: “We have a busy programme over the next few days with Arsenal on Friday at Borehamwood and a Checkatrade Trophy game at Wycombe Wanderers next Tuesday.
“Tonight’s team will include the two under 16 year olds and three under 18s as I keep an eye on the match against Arsenal. It’s a very big opportunity for them as this is the Benfica B team and are extremely talented.