The club officially announced on Wednesday that Jeff Hendrick, Aaron Lennon, Joe Hart and Adam Legzdins will leave the club when their contracts expire next week.
Right back Phil Bardsley has, however, signed a new deal to take him through to summer 2021.
Dyche will need to bring in replacements, and, asked whether the board accept gthe need for recruitment in the summer, he said: “We don’t know exactly what is going to happen with the market.
“I don’t know about our situation budget wise, I very rarely do.
“So I’ll have to wait and see, but there will need to be adaptations to the market, a push in the market at some point because we quite obviously have got to a very skinny squad.
“The facts of football are that we will have to invest more money.
“The shifting sands of football are probably shifting even more than they have done in recent years.”
None of the players out of contract were involved at Manchester City on Monday night, while the club worked hard to persuade Hendrick and Bardsley to agree new terms.
Hendrick decided against a new deal, but Bardsley – having been released effectively – was able to renegotiate a contract and rejoin the squad for the home game with Watford last night.
Dyche said: “It’s a bit quirky.
“We released him, then re-signed him three days later.
“It’s another body for us. We’re stretched to the limit at the minute.
“Joe, Aaron, Jeff and Adam, that’s them done.
“That’s the reality sometimes of life at Burnley, it is difficult.
“I chuckled in the right way the other night when someone said it’s the first time Sean Dyche has questioned his board in seven-and-a-half years.
“I think most boards would be happy to be only questioned once in seven-and-a-half years.
“I was quite proud of that. I thought that was a positive negative in my mind.”
Those absences and four key injuries meant Dyche could only name seven of the new allocation of nine substitutes.
But he insisted it wasn’t a message to the board: “There was some suggestion I was trying to prove a point with my bench. I wasn’t, that was my full hit.
“We had everything we had out there, the other night.”
“We’re still missing Barnes, we’re still missing Wood, we’re missing Gudmundsson, on the night we were missing Robbie Brady as well.
“That was every player we have got left.
“It wasn’t a show of anything other than the truth.”