Thad Cochran says he isn’t retiring, but Senate Republicans have to be concerned after the 79-year-old returned to D.C. this week from a medical absence so “disoriented” that he mistakenly kept saying “yes” on an amendment while an aide repeatedly told him to vote “no,” Politico reported.

The Mississippi senator, absent from Washington for about a month because of a urological issue, was reportedly “disoriented” and “frail” when answering questions from reporters in the hallway Tuesday, according to Politico. He also had to be escorted to the Senate chamber by an aide, who prevented the politician from wandering around to the wrong rooms.

When asked whether he would retire, Cochran replied, “Don’t believe everything you hear.”

When asked whether GOP leadership had forced him to return to Washington to vote, Cochran replied with a smile and said, “It’s a beautiful day outside.”

Cochran, who has spent 44 years in office, chairs the Senate Appropriations Committee, a critical seat responsible for legislating government spending. Observers say top Senate Republicans are desperate to prevent Cochran from retiring because it would add pressure to their already razor-thin majority.

His presence is specifically noteworthy for Senate Republicans’ upcoming vote on a budget measure that would make way for tax reform. Without Cochran, they could only afford to lose two other votes. Republican Sen. Rand Paul of Kentucky already declared his opposition Tuesday.

The 115th Congress is among the oldest in recent history, according to the Congressional Research Service. In fact, the average age of senators is 61.8 years, and more than half of the senators up for reelection will be over 65 by 2018.

LIST OF SENATORS OVER 80