The Hornets skipper lambasted Arsenal’s performance following their 2-1 loss at Vicarage Road on Saturday.
Per Mertesacker had headed the Gunners ahead before Deeney came off the bench to equalise from the penalty spot, with Tom Cleverley lashing home an injury-time winner for the hosts.
The result leaves Arsenal sixth in the Premier League, nine points adrift of leaders Manchester City, and saw Deeney question Arsene Wenger’s players.
“I’ve heard Wenger’s already blaming (the penalty) as the reason for why they lost,” Deeney told BT Sport.
“Well, I’m not going to be one to tell Mr Wenger about himself, but there’s a reason that they lost and it wasn’t because of one penalty.
“I have to watch what I say, but it’s about (having) a bit of cojones, is what I’ll say. Whenever I play against Arsenal, I’ll go up and think ‘let me whack the first one and see who wants it.’”
Wilshere, an unused substitute at Watford, is expected to start Arsenal’s Europa League group game at Red Start Belgrade this evening.
“As a player if your attitude is questioned, it’s horrible,” he said.
“I look around this team and you can’t question our character. People try and put us down, they always have.
“I don’t think the comments were justified. When we look back at the game we look back at ourselves and what we did wrong. I don’t think we can look back and question our character.
“We did certain things wrong but we certainly didn’t want to let the lead slip. We will move on.
“We have a game [tonight] and another big game at the weekend and we have seen with this team that the players can bounce back quick and we will do that.
“No one wants to hear those comments. But players are entitled to their opinions and to talk. That’s part of the modern-day game and we have to deal with that.
“All we can do is bounce back with a good performance tomorrow and at the weekend.”
Wenger, too, brushed off the criticism and said he “loves” his players.
“Everybody is entitled to talk,” he said.
“I think after the game sometimes the enthusiasm of what happened went overboard. We don’t listen too much to what people say — we try to analyse our own game and get on with it.
“I know who my players really are. In the last seven games we had six wins and one draw (before losing at Watford).
“After that, the comments, that’s part of the modern game, you have to realise that. I love my players and I trust their strength of character to respond quickly.”
Wenger also revealed Mathieu Debuchy is in line for his first Arsenal start of the season having played just 16 minutes in the last two-and-a-half years.
Petr Cech will start in goal while youngsters such as Reiss Nelson, Ainsley Maitland-Niles, and Joe Willock are likely to be involved.