The Hitech Grand Prix team-mates currently lie tenth (Vips) and 12th (Armstrong) in the 2022 championship, with one round remaining in Abu Dhabi.
Both have previously expressed interest in switching to IndyCar, with former Red Bull junior Vips approached by a well-established team that then elected to retain its current line-up for 2022.
Today Vips will pilot a Rahal Letterman Lanigan machine around the 1.7-mile short course at Sebring, while ex-Ferrari Driver Academy member Armstrong will run out for Dale Coyne Racing.
These should be seen as the most significant try-outs of the five drivers being evaluated, with Vips a potential replacement for Jack Harvey after his disappointing first season at RLL relative to team-mates Graham Rahal and Christian Lundgaard.
Coyne meanwhile is eager to expand his team to three cars for 2023, and Armstrong is a prime candidate along with 2022 Indy Lights champion Linus Lundqvist to join the already announced David Malukas.
Jake Dennis, an Avalanche Andretti Formula E driver who finished third in the 2020-21 championship, will have a first try in an IndyCar with Andretti Autosport.
Elsewhere, Meyer Shank Racing will run Tom Blomqvist, who last week helped the team to secure the IMSA SportsCar Championship with victory at Petit Le Mans.
The Anglo-Kiwi has concentrated primarily on sportscars in recent seasons, finishing runner-up in last year’s LMP2 category at Le Mans and in the World Endurance Championship, but in 2014 was second to Esteban Ocon in the Formula 3 European championship.
Former Juncos IMSA racer Agustin Canapino will drive a Juncos Hollinger Racing-Chevrolet in preparation for his demonstration runs in the car in his native Argentina, as reported last week.
And DCR will remain at Sebring for an extra day to test 2022 Indy Lights driver Danial Frost, who raced for HMD Motorsports w/Dale Coyne Racing last season and will do so again in 2023.
