Frank defends Johnson sale after Spurs jeered in Sunderland draw
Frank opted to sell Wales forward Johnson to Crystal Palace this week in a £35 million ($47 million) deal despite his 18-goal haul last season.
The move raised eyebrows given Johnson's finishing ability and Tottenham's lack of cutting edge, but the 24-year-old had largely lost his place to Kudus this season.
However, Kudus was forced off in the 19th minute with a left leg injury against Sunderland, leaving Johnson's absence keenly felt.
Although Ben Davies rewarded Tottenham's strong first half with a 30th-minute goal, they failed to kick on and Sunderland's Brian Brobbey bagged an 80th-minute equaliser.
"We lacked a little extra freshness. I looked at some teams last night. They just put three players on like for like," Frank began before he fielded a flurry of questions on Johnson.
"You know, decisions are made and decisions I'm backing in every aspect. There's always more bigger picture stuff to some of those decisions. Sometimes it can look like perfect timing. Sometimes it looks like not so perfect timing."
Asked if it was a risk to let Johnson go, Frank pointed out: "We took the decision before Mo got injured.
"We don't know how that looks like, so I think that's one thing and sometimes when you take that decision, sometimes you can't delay them if you want to for example.
"Sometimes, you know, the decisions make more sense further down the line and now there was an opportunity to sell a player, which the club hasn't been that good at in the past.
"So, there's just some games where you're very light and that happens for teams."
Tottenham are languishing in 13th place in the Premier League after their latest flop on home turf.
Fans had sarcastically chanted "boring Tottenham" during the drab goalless draw at Brentford in their previous match.
As the pressure mounts on Frank in his first season in charge, the former Brentford boss acknowledged Tottenham would try to bring in reinforcements during the January window.
"We are really, how can you say, alert," he said.
"The club really want to see what we can do to strengthen the squad and the team."