Josh Long/CNET

U.S. Magistrate Judge Paul S. Grewal has turned down Apple's recent request to include the Galaxy S4 in an ongoing lawsuit against Samsung.

In a ruling dated Wednesday, Grewal wrote that Apple's argument for including the Galaxy S4 in its lawsuit against Samsung is not persuasive enough and creates "undue prejudice" for Samsung as it defends itself against Apple's legal jabs.

According to Grewal:

Throughout the hearing, Apple warned that excluding the Galaxy S4 would result in yet another case with more claims of infringement and would require Apple to continue to play, in counsel's words, 'whack-a-mole' with Samsung. Apple presented the exact same argument to Judge Koh during an April 23, 2013 hearing during which she required them to set a schedule to drop products and patents. Judge Koh was not persuaded by this argument and neither is the undersigned. Apple already needs to dismiss without prejudice several products from this case and so a new trial would be likely regardless. Given the likely undue prejudice to Samsung and Judge Koh's directives regarding the management and progression of this case, the court DENIES Apple's request to add the Galaxy S4 to its contentions.

Apple last month asked U.S. District Court Judge Lucy Koh to add the Galaxy S4 to a Samsung lawsuit, citing alleged patent infringement. To adhere to Koh's request that the companies reduce the number of infringing devices, Apple offered to remove another device from its lawsuit to keep the same number of products.

As Grewal notes, however, that's not enough for the judges. In addition, Grewal states that because the Galaxy S4 is relatively new to the market, Samsung shouldn't be expected to deliver all of the required information in time for upcoming hearings.

The companies are waging court battles over alleged patent infringement on both sides. Last year, a jury awarded Apple $1.05 billion in damages from Samsung, but Koh lowered that to $639.4 million. She also ordered a new trial in November to determine whether certain products included in that judgement should have been cited as infringing.