The Blues took all three points thanks to goals from Sindre Walle Egeli and George Hirst, but their first-choice left-back wasn’t named in the squad, having played the full 90 minutes in the 5-3 defeat at Wrexham over the weekend.
“Leif is struggling from a heavy knock he got on Saturday, just above his knee,” McKenna explained.
“Absolutely no chance for today. We’ll have to see how he is over the next few days.”
Jacob Greaves replaced the left-back at Vicarage Road (Image: Ross Halls)
In his absence, Jacob Greaves stepped in at left-back, putting in an impressive display to help Town keep a clean sheet at Vicarage Road.
“He did really well,” McKenna said. “That’s probably two out of three games at left-back he’s done really well in this year.
“I think he can comfortably play that position really, really well. He’s got some good attributes for it and she showed them tonight.”
Town have most players fit and available, with Marcelino Nunez recovering from his ankle injury to make a cameo appearance at Wrexham before starting against Watford.
Jaden Philogene remains sidelined with an MCL injury (Image: Ross Halls)
However, Jaden Philogene remains sidelined with an MCL issue, with no clear picture on when he’ll be back in action.
“No, and it’s not me being vague and not trying to give anything away for the weekend,” McKenna replied when asked about the winger having a timeframe for his return. “It’s day-by-day.
“It’s a really delicate area, a really tricky injury.
“He’s made some progress again this week and he’s back out on the grass, but we’ll have to keep assessing him day-by-day.”