Pete Sampras says it will take time for Roger Federer to adjust to a new racket.
But Sampras believes Federer's struggles have more to do with confidence, not equipment.
"It just comes down to confidence. When Roger's playing well, he can play with a broomstick. He's that good."
Sampras once said he wished he switched to a larger racket head later in his career, and he believes it could help Federer.
"I think a bigger racket can help in certain areas, maybe on the high backhand. That's the shot I feel like it's helped me. Maybe a little bit more pop on the serve. But, you know, it's more racket, it's more power. Roger's forehand is such his bread and butter and if he's thinking twice about it, that's not a good thing."
Federer began experimenting with a new racket after his loss at the French Open. He is reportedly playing with a Wilson prototype with a 98-square-inch head. He usually plays with a 90-square-inch racket head.
Regardless of the racket, Sampras said winning matches is what will help Federer.
"So it's going to take some time. I mean, he needs to win some tough matches and just feel like ‑‑ you know, if people are asking him, he's thinking about it. I think it's worth trying, and I hope it helps him.
"I don't think Roger ‑‑ he's lost a few matches. I don't think he needs to panic and feel like he needs to change everything. He's still a great player and always will be. Just to try something a few weeks here would be fine. I will be curious to see if he plays with it at the Open."
Federer is also suffering from a bad back. He withdrew from the Rogers Cup without explanation. He is expected to play in Cincinnati this week.
Sampras cautioned that any equipment change could set a player's game back.
"You know, it's just mental, you know, gets in your head. Look at (Rory) McIlroy and his clubs. I mean, it takes one slight little thing to get you off kilter, and I just hope Roger just, if he sticks with this racket, can win some tough matches. Once he does that, he will be fine."