Rory McIlroy put a new putter in the bag and shot a level par 70 in the Travelers Championship last night.

The good news is that it was good enough to make the three-round cut by two shots on level par.

The bad news was that ditching the TaylorMade Red Spider after just four rounds resulted in his weakest performance of the week with the flat stick.

Having had 30, 32, 30 and 29 putts with the Spider between the US Open and the first two rounds at TPC River Highlands, McIlroy spent some time searching for a replacement putter before Saturday's third round and according to reports, settled on a TaylorMade TP Mullen model.

The result was 33 putts, leaving the Co Down man 73rd in the field for putting heading into the final round in Connecticut, 12 strokes behind Jordan Spieth on 12-under par.

It will be interesting to see what putter he uses in round four.

Having registered a -.933 for strokes gained putting in round one, and a -1.121 in round two, a -1.540 was not what McIlroy was looking for on Saturday.

In short, he gave away three shots on the greens to Spieth, who recovered from back to back bogeys at the 13th and 14th with three birdies in his last four holes.

After a 20-yard bunker shot stopped on the lip at the driveable 15th, setting up a tap-in birdie, the 23-year old Texan made a six-footer for a two at the 16th and then punched the air as he stroked in a 20 footer for birdie on the 18th.

Seeking his 10th PGA Tour win, Spieth's four-under 66 gave him a one-stroke on 12-under par from Boo Weekley (65) with Daniel Berger (66), just two behind.

Pádraig Harrington is eight strokes behind, tied for 21st, after a round that appeared to flicker out late in the day.

Tied for eighth starting the day, the 45-year-old made four birdies and three bogeys to remain inside the top 10 with three to play.

At six-under, he was within four shots of the lead but bogeys at the 16th and 17th, coupled with three birdies in the last four holes from Spieth, put paid to his title chances.