Rory McIlroy and Shane Lowry were quick to defend PGA Tour commissioner Jay Monahan for his handling of the COVID-19 crisis after getting off to fast starts in the Travelers Championship in Connecticut.

World No 1 McIlroy shot a seven-under 63 to lie tied second with Xander Schauffele and Viktor Hovland behind 60-shooting Canadian Mackenzie Hughes as Lowry posted a four-under 66 to share 17th place after the opening round.

The Offaly man was in demand after his round for his thoughts on the PGA Tour “bubble” having played a practice round on Tuesday with Brooks Koepka, Chase Koepka and Graeme McDowell, all of whom withdrew from the tournament following positive COVID-19 tests for caddies Ken Comboy and Ricky Elliott.

"I just kind of wish people would stop being so negative towards it," said Lowry, who played just nine holes with the Koepka's and McDowell and having tested negative twice was cleared by the PGA Tour to tee it up this week.

"I think we're very lucky to be back out playing. I've seen a lot of media coverage that is quite negative, and I don't like it. 

"I think the PGA TOUR, Jay, everybody involved has done a great job, and I as a professional golfer are very happy to be back to work and to be providing some entertainment for some people at home."

Explaining how he heard about the positive tests for Comboy and Elliott, Lowry said: "Ricky called me himself. I couldn't really believe it. To be honest I thought he was messing with me because he kind of is like that sometimes.

"Then as the guys pulled out, I contacted the Tour pretty quickly because I asked them what did they think I should do because I wanted to do the right thing. 

"But I don't think I was within enough contact with Ricky over the course of the nine holes we played on Tuesday. We're just taking precautions. I'm not going near the clubhouse all week, I wear my mask into scoring, I'm not allowed in for lunch now. I'm kind of just being as cautious as I can.

"But like I said, I spoke to Jay yesterday evening here at the club, and he said that I'm good to play. So I'm here to play, and I think it's obviously disappointing that a few people have got it, but not that it's inevitable, but it's the world we're living in at the minute.”

He added: “I think the first couple of weeks have been kind of a kick in the backside to all of us and to make sure that we do the right things when we're out there because even I'm guilty of it. I fist-bumped the first couple of weeks, there's no doubt. “

McIlroy echoed Lowry's thoughts on the PGA Tour's response to the positive tests, describing media calls for the tournament (or even the Tour) to be shut down as "silly".

"I thought Jay did a wonderful job yesterday, just relaying the information and where the PGA Tour stands and where we are going forward,” McIlroy insisted. 

"You hear one or two positive tests and people are panicking, and I saw a couple of calls to shut the tournament down, which is silly from my point of view. 

"You know, I thought he did a really good job explaining. There's been almost 3,000 tests administered. The percentage of positive tests is under a quarter of a per cent.

"I think as a whole, it's been going really well. There's a couple of loose ends that we needed to tidy up, and I think we've done that. So yeah, I feel like the mood and the tone of the event was probably lifted by Jay yesterday."

McIlroy eagled the 13th, birdied the 14th and two-putted the driveable 15th from 12 feet for another birdie before dropping his only shot at the day with a clumsy chip at the par-three 16th.

He birdied the 18th and turned in 32 despite missing five putts between six and 15 feet and had the patience to pick up four more shots on the front nine for his 63.

"For me especially, you get a little antsy and I start to maybe get a little quick if you're thinking that way," he said of the chances he missed. "You're not going to keep shooting nine holes of 3- or 4-under all the time, so you have to remind yourself of that."

Playing partners Bryson DeChambeau (65) and Phil Mickelson (64) also went well with the left-hander a popular post-round subject after the news emerged that he will get to play the US Open this year after the USGA made the top 70 in the world rankings (rather than the top 60) on March 15 exempt for Winged Foot.

"His longevity is incredible," McIlroy said of Mickelson. "It really is. I think the big thing about Phil is his resilience. I mean, he's won 44 times on Tour, which is an incredible number, but the amount of close misses he's had, as well, and the fact he kept coming back and kept coming back and played well and putting himself in position. 

"It looks from the outside he's never feared failure, and I think that's what's made him such a fan favourite is he goes for things and he takes on things. And he has a deep appreciation for his place in the game and the game of golf itself. Can I see myself out here at 50? It's 20 years down the line, but I'd like to think that I would still have the love for the game that Phil has at that age."

Mickelson has six runner-up finishes in the US Open and McIlroy would not begrudge him a win and the career Grand Slam.

"It would be an incredible story for our game, for the game of golf. But look, I think Phil has proved enough to everyone, three green jackets, a PGA, an Open Championship. If he doesn't win it, it's not a blemish on his career. 

"He's had a wonderful career, and no one should take anything away from him because to keep putting yourself in that position -- look, sometimes it happens, sometimes it doesn't. That's our game. He's handled all that really, really well. 

"But look, if it weren't me and he found himself in that position, I'd definitely be rooting for him."