Marcus Trescothick returns to the pavilion at the end of the day © Getty Images

Marcus Trescothick made the most emphatic statement to date that his rehabilitation is on track with an unbeaten 185 as Somerset made Northamptonshire regret their decision to bowl at Northampton.

With Michael Vaughan and Kevin Pietersen picking up injuries ahead of the first Test against West Indies it was another timely reminder of Trescothick's destructive ability, although he has repeatedly said he won't be rushing back to the international scene.

"I need a few more knocks like that and for my form to continue over a good period of time," Trescothick said. "I would play tomorrow if I thought that I was fit enough. But there are a few more hurdles for me to overcome before I am at that stage. I've stated my position a number of times in media interviews and I had a chat with Michael Vaughan last week so I think they know what the position is."

Trescothick has been in good nick throughout the early weeks of the season and took full advantage of benign conditions to reach his first first-class ton for a year. It took him 173 balls, and his only alarm came when Rob White missed a run-out chance on 91 as David Sales was left regretting his decision to bowl.

Fellow left-hander Justin Langer, who has been in prolific form, joined Trescothick in a second-wicket stand of 196. Seemingly set for his own century, Langer was caught at wide long-on off Monty Panesar, a second scalp for the left-arm spinner, who was the only wicket-taker as the other bowlers struggled against the in-form batting line-up.