Robbie Grossman
It is frankly remarkable what the Rangers have been able to accomplish offensively in 2023. Of the nine position players with more than 300 plate appearances so far in 2023, seven of them sport a wRC+ of 120 or better which is just absurd production. However, one player who hasn't performed well and who is the only position player with that much playing time for Texas that has posted a negative fWAR on the season is Robbie Grossman.
Grossman does serve a purpose as a switch-hitter who can play either corner outfield spot which does have some intrinsic value. However, the reality is that Grossman doesn't really bring a ton to the table when it comes to upside. He CAN play either corner outfield spot, but his -6 Outs Above Average this season points to him not being a great defender in either spot. Moreover, being a platoon busting switch-hitter only works if you can actually, well, hit and his 95 wRC+ and .233 batting average are the worst on the team amongst hitters with 300 plate appearances. In short, the Rangers can do better here.
Brock Burke
This is where the list gets trickier because the Rangers roster is really quite deep. For example, the bullpen has been a middle of the road group in 2023 by fWAR, but it is hard to point to specific names that have been true "problems" out of the bullpen for Texas this season. However, one name that does sort of stick out after a deeper look is Brock Burke.
On the surface, Burke has had a perfectly reasonable season with a 2.87 ERA in 38 appearances and one can appreciate his elite walk rate from the left side. However, he doesn't strike out a lot of batters and his 4.38 FIP and 86.1% strand rate points to a fair amount of luck on his side so far and the Regression Monster could come for him before too long. A quick look at his Statcast page also points to some concerns about the batted ball profile against him where he is decidedly meh. It won't be a shocker if he sticks around, but Texas may be better served moving him this offseason in favor of a peripherals upgrade while selling high on him.