That old trick knee of mine is flaring up again.

It’s throbbing so much that I am beginning to think that West Texas Republican voters are facing the prospect of a serious donnybrook in the race for the state Senate District seat now held by Amarillo businessman Kel Seliger.

My critics are all too willing to remind me that the trick knee isn’t nearly as reliable as I’ve suggested it is. But that’s all right. It’s telling me that Seliger is going to have to fend off some serious criticism from two GOP primary foes. The criticism well might center on the senator’s decision against endorsing Lt. Gov. Dan Patrick’s own re-election bid in 2018.

I have read Sen. Seliger’s comments on this decision. He said he’ll “support” Patrick — I presume with his vote. He just won’t declare his endorsement out loud in public, for the record.

Seliger’s decision drew a hair-trigger response from Amarillo restauranteur Victor Leal, who suggested that Seliger is turning his back on the Senate’s presiding officer. I am guessing that Leal is going to endorse Patrick, one of the Texas GOP’s more vivid ideologues. Seliger isn’t wired the same way, and my hunch is that his own legislative temperament — which differs greatly from Patrick — has compelled him to withhold his active endorsement of the lieutenant governor.

The third Senate District 31 Republican candidate, former Midland Mayor Mike Canon, likely will seek to gain some political leverage, too. He’s a TEA Party kind of guy, which also runs anathema to Seliger’s more measured and studied approach to legislating.

Seliger has told local media that he expects a tough fight. I will presume he’ll prepare for one as well. It is my hope that he preps for a bruising campaign and gets ready to rumble with Leal and Canon.

Leal is a known quantity in the northern half of the Panhandle; Canon’s base is in the Permian Basin. Seliger, a former Amarillo mayor, has managed to make his presence felt down yonder in the southern part of the sprawling district.

I’ve already revealed my bias in this race; I want Sen. Seliger to win the nomination, which in this district is tantamount to election.

The only bit of advice I can give Seliger — based on my trick knee — is to get his opposition research ready and to respond quickly and forcefully to the attacks that are sure to come his direction.