US Open Men's Singles Day 5 Tips: Karatsev the pick at underdog prices

• Djokovic and Fritz strong favourites

• Quarter three pick Paul back in action

• Karatsev today's selection

Tsitsipas and Ruud out as third round gets underway

Wednesday's winners get to play their third round games on Friday, but several big names won't be present on court. Stefanos Tsitsipas was shocked by Dominic Stricker, with the high-variance dynamic I've often discussed present again with Tsitsipas' mediocre return game causing further issues for the Greek man who often seems to get drawn into these battles with lower-ranked opposition in Grand Slams.

Furthermore, Casper Ruud was ousted by Zhizhen Zhang in five sets, and our pick for Q3 winner Tommy Paul almost came a cropper as well, needing to fight back from two sets down to eventually progress. However, the only drama for Novak Djokovic was a fall which he seemed fine after, dropping just six games in a routine victory.

A routine victory is anticipated again for the tournament favourite, who now faces Laslo Djere in his match on Friday. Djokovic is just 1.021/50 to get past his fellow Serb. Taylor Fritz is the other ultra short-priced favourite in action, as he faces the qualifier Jakub Menšík.

Paul facing tricky test

However, a few matches are perceived to be relatively competitive by the markets, and the first to discuss is Tommy Paul against Alejandro Davidovich Fokina.

The duo have already met twice this season on hard court with Paul winning on both occasions, and priced between 1.501/2 and 1.608/13 pre-match. Despite this, the American is now trading at 1.784/5, somewhat bigger than those prices early this year.

I think this lack of market support for Paul is due to the nature of his win over Roman Safiullin on Wednesday, in a battle which lasted five sets but perhaps crucially, only took just over three hours. There are four-set matches which last longer than this, so in terms of accumulated fatigue, this isn't quite the negative on Paul as perhaps it would be on Stricker, for example, whose win over Tsitsipas took an hour longer.

Both players have a strong record on hard court this year, although it's worth noting that Davidovich Fokina did come into this event with fitness doubts. The change in market price probably just about makes sense.

Shelton opposable for Karatsev match-up

One player I've been keen to oppose so far is Ben Shelton, with the big-serving American a favourite at 1.645/8 for his match against the inconsistent Aslan Karatsev. You never really quite know what you're going to get with Karatsev, but he has far better return numbers than Shelton, with less of a deficit on serve.

Shelton was fortunate in round two when opponent Dominic Thiem fell ill during their match, and I'm surprised to see him chalked up as favourite here.

Zhang potentially fatigued after two five-setters

Finally, after beating Ruud, Zhizhen Zhang's reward is being favourite at 1.715/7 against the Australian wildcard Rinky Hijikata. Zhang beat Hijikata as a slight underdog in the Phoenix Challenger in March so the odds have turned around since then, but after two five-setters against top 50 opposition, Zhang could well be pretty fatigued.

These have taken almost eight hours combined in court time, two hours more than Hijikata who surprisingly eased past Marton Fucsovics in round two.

Hijikata has an edge on hard court data (clearly in the market's mind in that earlier match-up this season) and with the fatigue element a big consideration for Zhang, I'd be more minded to have prices at a similar line to that match in March.