The Potters have come under fire from supporters for failing to bring in a striker in January, with a lack of goals being a primary cause of their relegation battles.
He told the Stoke Sentinel: "We did try to strengthen again in January, it wasn't something we were unaware of, but football is more complicated than that.
"We tried to spend money, but for whatever reason we weren't successful. Good strikers who will make a difference are not easy to find, as anyone in football will tell you.
"We tried to sign Daniel Sturridge from Liverpool for example, but he preferred West Bromwich Albion because he wanted to move to that area. We tried for Danny Ings, but once they let Sturridge go they wouldn't let him go."